U.S. Overseas Basing: Background and Issues for Congress

U.S. Overseas Basing: Background and Issues for Congress

U.S. Overseas Basing: Background and Issues
July 10, 2024
for Congress
Luke A. Nicastro
Since World War II, the U.S. military has maintained a large network of overseas bases (that is,
Analyst in U.S. Defense
military facilities located outside the United States and its territories). Currently, the U.S.
Infrastructure Policy
Department of Defense (DOD) manages or uses at least 128 overseas bases in at least 51

different countries. Policymakers cite a variety of strategic reasons for the maintenance of
Andrew Tilghman
overseas bases, including:
Analyst in U.S. Defense
Infrastructure Policy
• Facilitating rapid responses to military contingencies outside the United States;

• Deterring adversaries from attacking the United States or its allies and partners; and

• Assuring allied and partner nations of U.S. security commitments.

The United States typically acquires overseas basing rights through diplomatic arrangements with host nations, often in the
form of bilateral executive agreements. Within DOD, a variety of offices and organizations are involved in the management
of overseas basing activities, including the Office of the Secretary of Defense, the geographic combatant commands, and the
individual Services.
Congress’s role in overseas basing is significant, and includes appropriating funds for basing activities, setting certain
policies and requirements through legislation, and overseeing the executive branch’s management of basing posture and
security relationships with host nations. Overseas basing therefore presents a number of issues for congressional
consideration, including:
• How much funding should Congress appropriate for overseas basing activities?
• Does the executive branch’s approach to managing relations with nations that host U.S. bases align with
congressional priorities?
• Does the current overseas basing posture adequately support strategic and operational objectives?

Congressional Research Service

link to page 5 link to page 5 link to page 5 link to page 6 link to page 6 link to page 7 link to page 7 link to page 9 link to page 9 link to page 10 link to page 13 link to page 16 link to page 18 link to page 20 link to page 22 link to page 22 link to page 22 link to page 23 link to page 24 link to page 24 link to page 24 link to page 26 link to page 27 link to page 28 link to page 28 link to page 29 link to page 30 link to page 31 link to page 31 link to page 33 link to page 10 link to page 12 link to page 15 link to page 17 link to page 19 link to page 21 link to page 27 U.S. Overseas Basing: Background and Issues for Congress

Contents
Introduction ..................................................................................................................................... 1
Purpose ...................................................................................................................................... 1
Methodology ............................................................................................................................. 1
Background ..................................................................................................................................... 2
Defining Overseas Bases ........................................................................................................... 2
Why Does the United States Maintain Overseas Bases? .......................................................... 3
Historical Development ............................................................................................................ 3
Current Overseas Military Bases ..................................................................................................... 5
Overview ................................................................................................................................... 5
Indo-Pacific ............................................................................................................................... 6
Europe ....................................................................................................................................... 9
Middle East ............................................................................................................................. 12
Africa ...................................................................................................................................... 14
Central/South America and the Caribbean .............................................................................. 16
Authorities and Management ........................................................................................................ 18
Treaties and International Agreements.............................................................................. 18
Relevant Statutory Authorities .......................................................................................... 18
DOD Policy and Organizations ......................................................................................... 19
Issues for Congress ........................................................................................................................ 20
Resourcing Overseas Basing ................................................................................................... 20
Total Overseas Basing Costs ............................................................................................. 20
MILCON Appropriations .................................................................................................. 22
Operation & Maintenance (O&M) Appropriations ........................................................... 23
Managing Relations with Host Nations .................................................................................. 24
Negotiating Basing Rights ................................................................................................ 24
Reliable Access and Political Risk .................................................................................... 25
Burden Sharing ................................................................................................................. 26
Aligning Overseas Basing with Strategic and Operational Priorities ..................................... 27
Overseas Basing and National Strategy ............................................................................ 27
Overseas Basing and Distributed Operational Concepts .................................................. 29

Figures
Figure 1. Geographic COCOMs ...................................................................................................... 6
Figure 2. U.S. Overseas Bases in the Indo-Pacific .......................................................................... 8
Figure 3. U.S. Overseas Bases in Europe ....................................................................................... 11
Figure 4. U.S. Overseas Bases in the Middle East ........................................................................ 13
Figure 5. U.S. Overseas Bases in Africa ....................................................................................... 15
Figure 6. U.S. Overseas Bases in Central/South America and the Caribbean ............................... 17
Figure 7. DOD Military Construction Spending by Region, FY2007-FY2023 ............................ 23

Congressional Research Service

link to page 65 link to page 35 link to page 65 link to page 70 link to page 72 U.S. Overseas Basing: Background and Issues for Congress

Tables

Table B-1. Selected U.S. Overseas Bases ...................................................................................... 61

Appendixes
Appendix A. U.S. Overseas Basing by Country ............................................................................ 31
Appendix B. Selected U.S. Overseas Bases .................................................................................. 61
Appendix C. DOD Definitions and Methodological Issues .......................................................... 66

Contacts
Author Information ........................................................................................................................ 68

Congressional Research Service

U.S. Overseas Basing: Background and Issues for Congress

Introduction
Purpose
This report provides an overview of U.S. overseas military bases, as well as information
concerning their functions, management, resourcing, and related issues for congressional
consideration. Its contents are unclassified, and the terms and methods used herein may differ
from those used by the Department of Defense (DOD) or other executive branch organizations.1
Additionally, because of the unclassified nature of this report, classified materials—for example,
DOD’s Enduring Location Master List (ELML)—were not used in its preparation.2
Methodology
To identify active U.S overseas bases, CRS used a number of unclassified sources, the most
foundational of which were DOD’s annual Base Structure Reports (BSRs).3 Other U.S.
government sources used in its preparation included budget justification documents for military
construction (MILCON) at overseas locations; DOD press releases and public statements
(including individual unit and installation websites); executive reporting pursuant to the War
Powers Resolution; Department of State press releases, Integrated Country Strategies, and related
documentation; congressional testimony, reports, and related documentation; and information
provided by executive branch officials and organizations. In addition, media reports were used to
supplement government-provided information as necessary.
To characterize active U.S. overseas bases, this report sorts locations identified from the above
sources into one of two categories. The first, persistent bases, includes overseas sites that have
been continuously used by DOD for at least 15 years and at which the U.S. military exercises
some degree of operational control (this category tends to include DOD’s largest and most well-
known bases).4 The second, selected other U.S. military sites, includes overseas sites that do not
meet one or both of the criteria for persistent bases, but at which DOD maintains some sort of
territorially linked presence or access.5 This report does not include locations that DOD may use
on a temporary basis for military exercises or contingency operations without intending to make
persistent sites of U.S. military activity.6

1 For information on the ways in which DOD accounts for and characterizes its overseas bases, refer to Appendix C.
2 The ELML is a classified, comprehensive inventory of overseas U.S. military bases that DOD uses to “identify,
validate, and document locations that represent an enduring, strategic U.S. security interest for the foreseeable future.”
For more information, see DOD, “DOD Instruction 3000.12 Management of U.S. Global Defense Posture,” May 8,
2017, p. 11, https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/300012p.pdf; and DOD, “DOD
Instruction 4165.14 Real Property Inventory and Reporting,” September 8, 2023, p. 20,
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/416514p.pdf.
3 For more information about Base Structure Reports, refer to Appendix C.
4 Exercising operational control may include, among other things: U.S. control of ingress to/egress from base facilities,
DOD ownership or leasing of real property, U.S. rights to initiate and manage construction or facility maintenance
projects, and the exemption of a U.S. base area from host-nation legal jurisdiction.
5 This category includes both ally/partner-operated bases that host rotational or episodic U.S. deployments, as well as
DOD-operated bases established less than 15 years ago.
6 For additional information about how DOD classifies temporary locations, also known as contingency locations, see
Appendix C.
Congressional Research Service

1

U.S. Overseas Basing: Background and Issues for Congress

Applying the criteria developed above, this report identifies 68 persistent bases and 60 other U.S.
military sites across the Indo-Pacific, Europe, the Middle East, Africa, and Central/South America
and the Caribbean.
Background
Defining Overseas Bases
The U.S. Department of Defense maintains a network of thousands of buildings, fixed structures,
real property, and other defense infrastructure to carry out its mission to provide the nation with
military forces to deter aggression and prevail in conflict.7 The basic administrative unit into
which DOD groups its infrastructure is the installation, which is statutorily defined as any “base,
camp, post, station, yard, center, or other activity under the jurisdiction…[or] operational control
of the Secretary of a military department or the Secretary of Defense.”8 An installation or group
of installations may, in turn, serve as a base, which DOD defines as “a locality from which
operations are projected or supported.”9 Bases located outside the United States and its territories
are commonly referred to as overseas bases.10
Overseas bases perform or support a variety of military functions, including:
• Basing of personnel and equipment. The most elementary function of overseas
bases is to provide secure spaces for U.S. servicemembers, weapons systems,
munitions, and supplies, thus enabling the United States to maintain and employ
military capabilities in regions outside its territory. Bases serve as work sites
during both peacetime and wartime, supporting activities ranging from routine
office work to the launching of combat aircraft; larger installations may also
include housing for DOD personnel and their dependents, as well as morale,
welfare and recreation facilities.
• Domain awareness and area defense. Overseas bases may play an active role in
detecting, defending against, and otherwise countering adversary threats to U.S.
and allied/partner forces, facilities, and territory (by hosting, for example, radar
facilities or ground-based missile interceptor sites).
• Maintenance and repair. Overseas bases may host specialized facilities,
equipment, and personnel to maintain, repair, and overhaul weapons systems and
other defense equipment outside of U.S. territory. Examples of such facilities

7 DOD, National Defense Strategy, November 2022, https://media.defense.gov/2022/oct/27/2003103845/-1/-1/1/2022-
national-defense-strategy-npr-mdr.pdf. See also United States European Command (EUCOM), “About the Command,”
https://www.eucom.mil/about-the-command; United States Central Command (CENTCOM), CENTCOM Priorities,
https://www.centcom.mil/ABOUT-US/COMMAND-PRIORITIES/; and United States Indo-Pacific Command
(USINDOPACOM), “Area of Responsibility,” https://www.pacom.mil/About-USINDOPACOM/USPACOM-Area-of-
Responsibility/.
8 10 U.S.C. §2801.
9 DOD also offers two additional definitions for base: 1) “An area or locality containing installations which provide
logistics or other support”; and 2) “Home airfield or home carrier”. DOD, DOD Dictionary of Military and Associated
Terms, May 2023, p. 19.
10 For the purposes of this report, an overseas base is defined as any U.S. base located in the territory of a foreign
country, irrespective of its geographical proximity to the United States. Thus, a base located in the Bahamas meets this
definition, while one located in Guam does not. Some scholars have also used the term sovereign basing to describe the
practice of maintaining extraterritorial military facilities in peacetime. See, for example, Sebastian Schmidt, Armed
Guests: Territorial Sovereignty and Foreign Military Basing (New York: Oxford University Press, 2020).
Congressional Research Service

2

link to page 31 link to page 22 link to page 22 U.S. Overseas Basing: Background and Issues for Congress

may include vehicle maintenance facilities, aircraft maintenance hangars, and
naval drydocks.
• Training and exercises. Overseas bases may contain training and exercise areas
intended to maintain and enhance U.S. and allied/partner readiness, test plans and
concepts, and demonstrate and improve interoperability.
Why Does the United States Maintain Overseas Bases?
DOD considers the placement and organization of overseas bases—together with the positioning
of forces and the structuring of international security agreements—to constitute its global defense
posture.11 According to DOD Instruction 3000.12, DOD’s global defense posture “is the
fundamental enabler of U.S. defense activities and military operations overseas and is also central
to defining and communicating U.S. strategic interests to allies, partners, and adversaries.”12
Considered broadly, overseas bases support the ability of the United States to project and sustain
military power beyond its territorial bounds. They enable DOD to maintain a persistent presence
in areas that the U.S. government determines are important to the national interest, and can
facilitate rapid responses to sudden crises or emergencies. They also signal U.S. intentions to
other international actors, which may support a variety of strategic aims.13 For instance, the
presence of overseas bases in a region outside U.S. territory may communicate to allies and
adversaries alike that the United States views geostrategic developments there as directly relevant
to its national security. The presence of overseas bases may also contribute to the defensibility of
ally/partner territory, and deny U.S. rivals or adversaries access to strategically significant
locations.14
For a more detailed consideration of the potential advantages and drawbacks of overseas basing,
refer to the “Overseas Basing and National Strategy” subsection of this report’s “Issues for
Congress” section.
Historical Development
Overseas basing has played a significant role in recent U.S. military history, and much of DOD’s
current footprint abroad continues to reflect decisions made in the last century (of the 68
persistent military bases identified in this report, for example, 56 were established during the
Cold War).
Although the first permanent military facilities abroad date to the late 19th century, overseas
basing did not play a major role in U.S. strategy until World War II.15 Following America’s entry

11 DOD, DOD Instruction 3000.12 (“Management of U.S. Global Defense Posture”), May 8, 2017, p. 6, available at
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/300012p.pdf.
12 Ibid.
13 For a more detailed discussion of the role of overseas basing in current U.S. strategy, refer to the “Authorities and
Management” section of this report.
14 See, for example, discussion of potentially expanding the U.S. presence in Gabon and Equatorial Guinea to forestall
the potential establishment of a Chinese military base. Michael Phillips, “U.S.-China Tensions Have a New Front: A
Naval Base in Africa,” The Wall Street Journal, February 10, 2024.
15 The first such sites were coaling stations leased by the U.S. Navy in Mexico (1869), Samoa (1878), and Hawaii
(1887). Following the Spanish-American War (1898), bases were established in the newly-annexed territories of the
Philippines and Guam, as well as at Guantanamo Bay in the independent Republic of Cuba. The United States also
established bases in Panama to secure the Canal Zone, as well as in China to protect U.S. citizens and commercial
interests. See Seward W. Livermore, “American Naval Base Policy in the Far East, 1850-1914,” The Pacific Historical
(continued...)
Congressional Research Service

3

U.S. Overseas Basing: Background and Issues for Congress

into that conflict, the U.S. military established and used hundreds of overseas bases to support its
combat operations. These overseas bases included locations in Europe and the Pacific (the U.S.
Army Air Forces used over 200 airfields in the United Kingdom alone, for example), as well as
sites outside the war’s main theaters (e.g., Natal-Fortaleza in Brazil, Camp Amirabad in Iran).16
After 1945, the United States continued to use certain of these locations, along with newly
established bases in the territories of defeated Axis powers, to support occupation and
reconstruction activities.17 Although some policymakers did not expect this global presence to last
longer than a few years, the onset of the Cold War in the late 1940s led the United States to
maintain and expand its network of overseas bases, particularly in Western Europe and East
Asia.18 This footprint quickly became a major factor in U.S. and allied strategic planning,
enabling the projection of military power into distant, geopolitically contested regions.19
Although certain core aims of U.S. strategy during the Cold War remained consistent (e.g., to
deter—and failing that, prevail in—conflict with the Soviet Union), DOD’s overseas basing
posture during this period was not static. In some cases, unforeseen political developments, such
as the French government’s 1966 decision to expel from its territory all military forces under
foreign command, could result in base closures.20 In other cases, changing military requirements,
such as those stemming from U.S. involvement in the Vietnam War, could lead to the rapid
expansion of basing in a particular region.21 In 1991—the last year of the Cold War—DOD
reported maintaining 134 bases in 18 different countries, with locations in Germany, the United
Kingdom, Japan, South Korea, and the Philippines accounting for the majority of listed bases.22
The fall of the Soviet Union led to significant changes in America’s overseas basing posture.
Without a superpower rival, U.S. policymakers assessed that a smaller military presence abroad
would suffice to provide for the nation’s security, and closed dozens of bases from the North
Atlantic to Southeast Asia.23 In addition, the relative importance of the Middle East to DOD’s

Review Vol. 13, No. 2 (Jun., 1944); Michael Broadhead et al., The Panama Canal: An Army’s Enterprise (Washington,
D.C.: U.S. Army Center of Military History, 2009); and CRS Report R47589, U.S. Defense Infrastructure in the Indo-
Pacific: Background and Issues for Congress
16 Imperial War Museum, “American Airmen in Britain During the Second World War,” 2023,
https://www.iwm.org.uk/history/american-airmen-in-britain-during-the-second-world-war; Stetson Conn and Byron
Fairchild, United States Army in World War II: The Framework of Hemisphere Defense (Washington, D.C.: U.S. Army
Center of Military History, 1989), pp. 311-330; and T.H. Vail Motter, United States Army in World War II: The
Persian Corridor and Aid to Russia (Washington, D.C.: U.S. Army Center of Military History, 1952), p. 214.
17 The principal Axis powers were Germany, Italy, and Japan.
18 President Franklin Roosevelt, for instance, stated during the Yalta Conference that U.S. troops were unlikely to stay
in Europe for longer than two years. Charles Stefan, “Yalta Revisited,” Presidential Studies Quarterly, Vol. 23, No. 4,
(Fall, 1993), pp. 756-757, https://www.jstor.org/stable/27551152.
19 For an analysis of Cold War basing posture and its role in U.S. foreign policy and national strategy, see C.T. Sandars,
America’s Overseas Garrisons: The Leasehold Empire (New York: Oxford University Press, 2000).
20 This decision was taken in the broader context of France’s withdrawal from the North Atlantic Treaty Organization
(NATO) integrated command structure. See Eric Stein and Dominique Carreau. “Law and Peaceful Change in a
Subsystem: ‘Withdrawal’ of France from NATO.” The American Journal of International Law, Volume 62, No. 3
(1968): 577–640.
21 During the conflict’s peak, the United States maintained at least 26 “major base camps” across South Vietnam.
Carroll Dunn, Base Development in South Vietnam, 1965-1970 (Washington, D.C.: U.S. Army, 1991), p. 135.
22 CRS analysis of DOD’s FY1991 Base Structure Report (BSR), https://apps.dtic.mil/sti/tr/pdf/ADA242825.pdf.
Unlike more recent BSRs, which report information for sites, the FY1991 BSR reports by installation, making its
methodology similar to that of this report. CRS, however, cannot determine the exact degree of correspondence
between the methodology of the FY1991 BSR and that of this report, so the findings of the former may be used as a
broad baseline for historical comparison.
23 Countries that saw U.S. base closures included the Philippines, Germany, and South Korea. As one planning
(continued...)
Congressional Research Service

4

U.S. Overseas Basing: Background and Issues for Congress

global posture increased—particularly during the First Gulf War and again following the terror
attacks of September 11, 2001—and the United States established new bases in the region.
Although DOD’s footprint in Europe and the Indo-Pacific shrank during the 1990s and early
2000s, the reorientation of U.S. strategy around great power competition led to a reversal of this
trend by the mid-2010s.24 In Europe, the perceived resurgence of Russia as a geopolitical threat—
particularly after the 2014 and 2022 invasions of Ukraine—informed decisions to base U.S.
forces in new locations (e.g., Poland) and reactivate U.S. bases in former locations (e.g.,
Iceland).25 In the Indo-Pacific, strategic competition with the People’s Republic of China—the
U.S. military’s “pacing threat”—motivated DOD to deploy more forces to the region, expand
existing infrastructure, and obtain access to new sites in Australia, the Philippines, Papua New
Guinea, and elsewhere.26
Compared to its posture during the Cold War, DOD’s current overseas basing posture—
particularly since 2010—relies less on large, U.S.-operated installations and more on the
rotational use of ally/partner-operated sites (an approach sometimes referred to as “places, not
bases”).27 As Congress and DOD look to the future, the need potentially to support more
diversified and distributed operational concepts—for example, the Air Force’s Agile Combat
Employment (ACE)—may prompt further changes to DOD’s overseas basing posture.28
Current Overseas Military Bases
Overview
From a regional and joint perspective, the six geographically organized combatant commands
(COCOMs) provide oversight and theater-level direction of the strategic and operational
dimensions of DOD’s overseas basing posture (see Figure 1).

document put it in 2006, the post-Cold War years saw DOD “mak[e] long overdue adjustments to U.S. basing by
moving away from a static defense in obsolete Cold War garrisons and placing emphasis on the ability to surge quickly
to trouble spots across the globe.” DOD, Quadrennial Defense Review Report, February, 2006, p. v.
24 For more information on the role of great power competition in U.S. strategy, see CRS Report R43838, Great Power
Competition: Implications for Defense—Issues for Congress.
25 Poland, which was aligned with the Soviet Union during the Cold War, now hosts about 10,000 U.S. troops. Iceland
hosted U.S. forces at Keflavik from 1951 until 2006, and then again from 2016 through today. See Polish Ministry of
National Defence, “Increasing the U.S. Military Presence in Poland,” https://www.gov.pl/web/national-defence/
increasing-the-us-military-presence-in-poland; and Atlantic Council, “Cast Off By the United States A Decade Ago,
Keflavik is Again a Key Lookout,” May 7, 2018, https://www.atlanticcouncil.org/blogs/new-atlanticist/cast-off-by-the-
united-states-a-decade-ago-keflavik-is-again-a-key-lookout/.
26 For more information on DOD’s Indo-Pacific basing posture, see CRS Report R47589, U.S. Defense Infrastructure
in the Indo-Pacific: Background and Issues for Congress.
27 See, for example, former Chairman of the Joint Chiefs of Staff General Mark Milley’s remarks on the subject in
Hearing on the Fiscal Year 2023 Defense Budget Request, Testimony of the Chairman of the Joint Chiefs of Staff
Army General Mark Milley, House Armed Services Committee, 118th Cong., 1st sess., April 5, 2022. See also
“Making ‘Places, Not Bases’ A Reality,” Colonel Michael Pietrucha, U.S. Naval Institute, October 2015,
https://www.usni.org/magazines/proceedings/2015/october/making-places-not-bases-reality.
28 For more information on ACE, see CRS In Focus IF12694, Defense Primer: Agile Combat Employment (ACE)
Concept, by Sarah Gee and Luke A. Nicastro.
Congressional Research Service

5

link to page 35 link to page 65
U.S. Overseas Basing: Background and Issues for Congress

Figure 1. Geographic COCOMs

Source: FY2023 Agency Financial Report, DOD, November 2023, p. 17. Available online at
https://comptrol er.defense.gov/Portals/45/Documents/afr/fy2023/DoD_FY23_Agency_Financial_Report.pdf.
The following sections provide broad overviews of U.S. basing, regionally organized by COCOM
areas of responsibility (AOR).29 More detailed, country-level information on current overseas
bases is provided in the Appendix A.
Indo-Pacific
For the purposes of this report, the Indo-Pacific region corresponds to the AOR of the U.S. Indo-
Pacific Command (INDOPACOM).30 CRS identified 24 persistent bases and 20 other military
sites to which DOD has access within the region.31 As of March 2024, approximately 81,000
active-duty servicemembers were permanently assigned to overseas bases in the Indo-Pacific,
with the largest number assigned to locations in Japan (54,774) and South Korea (24,234).32
U.S. forces assigned to overseas bases in the Indo-Pacific include: Army and Marine Corps
ground units (including the Army’s 2nd Infantry Division, based in South Korea, and the Marine
Corps’ III Marine Expeditionary Force, based in Okinawa); Navy warships (including an aircraft
carrier, destroyers, cruisers, and amphibious assault ships, all based in Japan); and Army, Navy,
Marine Corps, and Air Force aircraft (including rotary-wing, fighter, electronic attack, bomber,
airlift, tanker, and other aircraft, primarily based in mainland Japan, Okinawa, and South

29 The exception to this is Central/South America and the Caribbean, for which responsibility is split between U.S.
Northern Command (NORTHCOM) and U.S. Southern Command (SOUTHCOM).
30 The state of Hawaii and the territories of Guam and the Northern Mariana Islands are also located within the
INDOPACOM AOR, but U.S. bases in those areas are excluded from the scope of this report (see “Methodology”
section above). For a discussion of alternative definitions of the region, see CRS Report R47589, U.S. Defense
Infrastructure in the Indo-Pacific: Background and Issues for Congress, p. 1.
31 Refer to Appendix B of this report for a comprehensive list of the persistent bases and other military sites identified
in this report.
32 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

6

link to page 35 U.S. Overseas Basing: Background and Issues for Congress

Korea).33 The U.S. military presence in Japan is overseen by U.S. Forces Japan, and the U.S.
military presence in South Korea is overseen by U.S. Forces Korea.34 The headquarters of
INDOPACOM is located outside Honolulu, Hawaii.35
The Indo-Pacific is routinely described by DOD officials as the “priority theater.”36 The 2022
National Security Strategy characterizes the Indo-Pacific as the “epicenter of 21st century
geopolitics,” and the 2022 National Defense Strategy identifies attempts by the People’s Republic
of China (PRC) to “refashion the Indo-Pacific region” as part of “the most comprehensive and
serious challenge to U.S. national security.”37 In addition to strategic competition with the PRC,
other core regional security interests include deterring and potentially defending against threats
emanating from Russia and North Korea.38 Overseas basing in the region is seen by some analysts
and policymakers as a critical enabler of U.S. military operations in a potential great power
conflict (particularly involving the PRC).39 The Indo-Pacific is also the focus of a congressionally
established set of defense investments and activities known as the Pacific Deterrence Initiative.40

33 Refer to the Indo-Pacific section of Appendix A for more information. See also “Posture: Overview Briefing,”
USINDOPACOM, January 2024, on file with the authors.
34 U.S. Forces Japan, “About U.S. Forces Japan,” https://www.usfj.mil/About-USFJ/; and U.S. Forces Korea, “About
U.S. Forces Korea,” https://www.usfk.mil/About/USFK/.
35 USINDOPACOM, “About USINDOPACOM,” https://www.pacom.mil/About-USINDOPACOM/.
36 See, for instance, Jim Garamone, “Defense Official Says Indo-Pacific is the Priority Theater,” DOD News, March 9,
2022, https://www.defense.gov/News/News-Stories/Article/Article/2961183/defense-official-says-indo-pacific-is-the-
priority-theater-china-is-dods-pacing/.
37 The White House, National Security Strategy, October 2022, p. 37, https://www.whitehouse.gov/wp-
content/uploads/2022/10/Biden-Harris-Administrations-National-Security-Strategy-10.2022.pdf; and DOD, National
Defense Strategy, October 2022, p. 4, 2003103845/-1/-1/1/2022-national-defense-strategy-npr-mdr.pdf.
38 See, for example, the 2024 statement of INDOPACOM Commander Admiral John Aquilino before the House Armed
Services Committee. Admiral John C. Aquilino, “2024 INDOPACOM Statement for the Record,”
https://www.congress.gov/118/meeting/house/116960/witnesses/HHRG-118-AS00-Wstate-AquilinoJ-20240320.pdf.
For more information on the strategic implications of great power competition, see CRS Report R43838, Great Power
Competition: Implications for Defense—Issues for Congress, by Ronald O'Rourke.
39 For more information, see discussion in CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific:
Background and Issues for Congress, pp. 4-7.
40 For more information, see CRS In Focus IF12303, The Pacific Deterrence Initiative: A Budgetary Overview.
Congressional Research Service

7

U.S. Overseas Basing: Background and Issues for Congress

Figure 2. U.S. Overseas Bases in the Indo-Pacific

Source: CRS analysis of unclassified U.S. government documentation (including DOD budget documents, Base
Structure Reports, official unit/installation webpages, press releases, Department of State documents,
congressional testimony, and information provided by executive branch officials to CRS).
Notes: The “Persistent” label describes a site that has been used consistently by DOD for at least 15 years and
at which DOD exercises some degree of operational control. Bases in Guam and other U.S. territories are not
depicted. Acronyms: AB=Air Base, CS=Communications Station, MCAS= Marine Corps Air Station, MCB= Marine Corps
Base, MCI=Marine Corps Installation, NAF=Naval Air Facility, NB=Naval Base, NCS=Naval Communication Station,
NB=Naval Base, NSF=Naval Support Facility, USAG=U.S. Army Garrison, USFA=U.S. Fleet Activity.
Congressional Research Service

8

link to page 65 U.S. Overseas Basing: Background and Issues for Congress

Europe
For the purposes of this report, Europe corresponds with the United States European Command
(EUCOM) AOR. CRS identified 31 persistent bases and 19 other military sites to which DOD has
access in the region.41 As of March 2024, approximately 67,200 active-duty servicemembers were
permanently assigned to overseas bases in Europe, with the largest contingents assigned to
locations in Germany (35,068), Italy (12,375) and the United Kingdom (10,058).42 However, as
of June 2024, thousands of additional servicemembers are present in Europe on rotational
deployments or other temporary assignments. In June 2024, the White House stated in a letter to
congressional leaders that “approximately 80,000 United States Armed Forces personnel are
assigned or deployed to North Atlantic Treaty Organization [NATO] countries in Europe,
including those deployed to reassure our allies and to deter further Russian aggression.”43
U.S. forces assigned to overseas bases in Europe include: Army ground units; Navy warships
(including destroyers and an amphibious command ship, based in Spain and Italy); and Army,
Navy, and Air Force aircraft (including rotary-wing, fighter, electronic attack, bomber, airlift,
tanker, and other aircraft). EUCOM is headquartered in Stuttgart, Germany, although its three
military service components maintain headquarters elements at other locations.44
The U.S. military presence in Europe has increased in response to Russia’s 2022 invasion of
Ukraine. In June 2022, for example, a DOD press release claimed that, since the invasion, DOD
had “deployed or extended over 20,000 additional forces to Europe in response to the Ukraine
crisis, adding additional air, land, maritime, cyber, and space capabilities.”45 Prior to this surge,
the Army maintained three brigade combat teams in Europe; since then, DOD has announced
permanent forward stationing of a corps forward headquarters, a garrison command, a field
support battalion, two squadrons of F-35s, an air defense artillery brigade headquarters, a short-
range air defense battalion, a combat sustainment support battalion headquarters, and an engineer
brigade headquarters.46
U.S. basing in Europe is closely integrated with NATO activities and objectives. Many U.S. bases
host NATO organizations and perform NATO-related functions, and every European host nation
covered in this report (except Kosovo and Cyprus) is a NATO member.47 According to the

41 Refer to the Appendix B of this report for a comprehensive list of the persistent bases and other military sites
identified in this report.
42 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
43 Aside from Kosovo and Cyprus, every European country in which DOD maintains overseas bases is a NATO
member. The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the
Senate regarding the War Powers Report,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/.
44 U.S. Army Europe and Africa is headquartered at U.S. Army Garrison Wiesbaden, U.S. Air Forces in Europe and Air
Forces Africa is headquartered at Ramstein Air Base, and U.S. Naval Forces Europe and Africa is headquartered at
Naval Support Activity Naples. DOD, “U.S. European Command Headquarters,” https://www.defense.gov/Multimedia/
Photos/igphoto/2003028524/. See also EUCOM, “History,” https://www.eucom.mil/about/history.
45 DOD, “Fact Sheet - U.S. Defense Contributions to Europe,” June 29, 2022,
https://www.defense.gov/News/Releases/Release/Article/3078056/fact-sheet-us-defense-contributions-to-europe/. In
April 2022, EUCOM claimed the region hosted “just shy of 20,000 deployed service personnel who are not normally
stationed in Europe,” including two division headquarters, and five brigade combat teams. “House Armed Services
Committee Holds Hearing on National Security Challenges in Europe”, 118th Cong., April 26, 2023.
46 DOD, “Fact Sheet - U.S. Defense Contributions to Europe,” June 29, 2022, https://www.defense.gov/News/Releases/
Release/Article/3078056/fact-sheet-us-defense-contributions-to-europe/.
47 NATO, “About Us,” https://www.nato.int/nato-welcome/.
Congressional Research Service

9

U.S. Overseas Basing: Background and Issues for Congress

EUCOM Commander, Russia is the central security issue in the region, constituting a “formidable
and unpredictable threat that will challenge U.S. and European interests for the foreseeable
future.”48 Europe is also the focus of a set of U.S. defense investments and activities known as the
European Deterrence Initiative (EDI).49

48 U.S. Congress, House Committee on Armed Services, Statement of General Christopher Cavoli, United States Army,
U.S. European Command, 118th Cong., 1st sess., April 26, 2023, p. 3.
49 See CRS In Focus IF10946, The European Deterrence Initiative: A Budgetary Overview for more information.
Congressional Research Service

10

U.S. Overseas Basing: Background and Issues for Congress

Figure 3. U.S. Overseas Bases in Europe

Source: CRS analysis of unclassified U.S. government documentation (including DOD budget documents, Base
Structure Reports, official unit/installation webpages, press releases, Department of State documents,
congressional testimony, and information provided by executive branch officials to CRS).
Notes: The “Persistent” label describes a site that has been used consistently by DOD for at least 15 years and
at which DOD exercises some degree of operational control. Acronyms: AB=Air Base, NAS=Naval Air Station,
NB=Naval Base, NB=Naval Base, NS=Naval Station, NSA=Naval Support Activity, NSF=Naval Support Facility,
RAF=Royal Air Force, USAG=U.S. Army Garrison.

Congressional Research Service

11

link to page 65 U.S. Overseas Basing: Background and Issues for Congress

Middle East
For the purposes of this report, the Middle East corresponds with the U.S. Central Command
(CENTCOM) AOR.50 CRS identified eight persistent bases and 11 other military sites to which
DOD has access in the Middle East.51 As of March 2024, approximately 5,400 active-duty
servicemembers were permanently assigned to overseas bases in the Middle East, with the largest
number assigned to locations in Bahrain (3,479).52 As of June 2024, thousands of additional
servicemembers were present on rotational deployments or other temporary assignments.
According to a June 2024 letter submitted by the Biden Administration to congressional leaders,
this number includes approximately 3,813 servicemembers in Jordan and 2,321 servicemembers
in Saudi Arabia.53
As part of the U.S. response to the ongoing Israel-Hamas conflict, Houthi attacks on international
shipping, and related geopolitical developments, DOD deployed additional servicemembers and
units to the Middle East in 2023 and 2024. In October 2023, DOD announced the deployment of
a carrier strike group, a Terminal High Altitude Area Defense battery, and additional Patriot
battalions to the Middle East.54 In December 2023, DOD announced the commencement of a
multinational security initiative in the Red Sea (Operation Prosperity Guardian), and in January
2024 began launching air and missile strikes against Houthi targets in Yemen and alleged Iranian-
linked militias in Iraq.55 U.S. bases in Iraq, Syria, and Jordan have also been subjected to
intermittent drone and missile attacks since October 2023.56
CENTCOM is headquartered in Tampa, Florida, and operates a forward headquarters at Al Udeid
Air Base in Qatar.57 In March 2024, the CENTCOM commander identified three “lines of effort”
for his command: “deterring Iran, countering violent extremist organizations, and competing
strategically [i.e., with Russia and China].”58 Compared to other regions, overseas basing in the

50 The CENTCOM AOR also includes countries located in Central Asia; however, because the United States does not
appear to maintain any publicly acknowledged bases in that region, this section confines its attention to the Middle
East.
51 Refer to Appendix B of this report for a comprehensive list of the persistent bases and other military sites identified
in this report.
52 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
53 The White House, Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report, June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-actions/2024/
06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-powers-
report/.
54 DOD, “Statement from Secretary of Defense Lloyd J. Austin III,” October 21, 2023,
https://www.defense.gov/News/Releases/Release/Article/3564874/statement-from-secretary-of-defense-lloyd-j-austin-
iii-on-steps-to-increase-for/. Figures for total U.S. regional troop presence cited in January 2024 media reports have
ranged from 50-60,000. See, for example, “Who Are the Houthis?” Financial Times, January 11, 2024. See also
discussion in CRS Report R47828, Israel and Hamas Conflict In Brief: Overview, U.S. Policy, and Options for
Congress.
55 For more information, see CRS Insight IN12301, Houthi Attacks in the Red Sea: Issues for Congress and CRS
Insight IN12309, Iraq: Attacks and U.S. Strikes Reopen Discussion of U.S. Military Presence.
56 As of June 2024, three U.S. servicemembers had been killed by such attacks. According to one media report, a DOD
official stated that U.S. servicemembers in Iraq, Syria, and Jordan had been attacked a combined 165 times between
October 17, 2023, and January 29, 2024. Lara Seligman, “Enemy Drone Evaded Detection by Trailing U.S. Drone
Landing at Jordan Base,” PoliticoPro, January 29, 2024, https://subscriber.politicopro.com/article/2024/01/jordan-
drone-iran-biden-00138363?source=email.
57 CRS In Focus IF11428, United States Central Command, by Nathan J. Lucas and Brendan W. McGarry.
58 General Michael “Erik” Kurilla, “Statement for the Record Before the Senate Armed Services Committee,”
USCENTCOM, March 7, 2024, at https://www.centcom.mil/about-us/posture-statement/.
Congressional Research Service

12

U.S. Overseas Basing: Background and Issues for Congress

Middle East (particularly Iraq and Syria) has been the subject of considerable recent controversy,
both within the United States and internationally.59
Figure 4. U.S. Overseas Bases in the Middle East

Source: CRS analysis of unclassified U.S. government documentation (including DOD budget documents, Base
Structure Reports, official unit/installation webpages, press releases, Department of State documents,
congressional testimony, and information provided by executive branch officials to CRS).

59 For more information, see CRS Insight IN12309, Iraq: Attacks and U.S. Strikes Reopen Discussion of U.S. Military
Presence.
Congressional Research Service

13

U.S. Overseas Basing: Background and Issues for Congress

Notes: The “Persistent” label describes a site that has been used consistently by DOD for at least 15 years and
at which DOD exercises some degree of operational control. Acronyms: AB=Air Base, NSA=Naval Support Activity.
Africa
For the purposes of this report, Africa corresponds with the U.S. Africa Command (AFRICOM)
AOR. CRS identified two persistent bases and seven other military sites to which DOD has
access in the region. AFRICOM characterizes sites in the latter category as “posture locations,”
which it describes as locations with “minimal permanent U.S. presence, [that] have low-cost
facilities and limited supplies…to perform critical missions and quickly respond to
emergencies.”60 As of March 2024, approximately 1,150 active-duty servicemembers were
permanently assigned to overseas bases in Africa, with the largest number assigned to locations in
Djibouti (406).61 The number of active-duty servicemembers at overseas bases in Africa on
rotational or other duty assignments is likely higher—for example, the Navy has reported the
presence at Djibouti’s Camp Lemonnier of “approximately 4,000 U.S., joint, and allied forces
military and civilian personnel.”62 AFRICOM is headquartered in Stuttgart, Germany.63
AFRICOM is the newest geographic COCOM, and its AOR contains fewer permanently assigned
servicemembers than that of any other COCOM. In his March 2024 Posture Statement before the
Senate Armed Services Committee, the AFRICOM commander described violent extremist
organizations and the expansion of PRC and Russian influence as the major threats to U.S.
interests in the region.64 Compared to basing in other regions, U.S. posture in Africa has been
particularly dynamic in 2024. In January 2024, The Wall Street Journal reported that DOD was
seeking to establish additional bases in coastal West Africa—specifically in Ghana, Côte d’Ivoire,
and Benin—to support unmanned aerial surveillance operations.65 And in March 2024, the
Nigerien government revoked its Status of Forces Agreement with the United States, leading
DOD to announce it would withdraw from the country (which had previously hosted two U.S.
bases) by September 15, 2024.66

60 AFRICOM, "Statement of General Michael E. Langley before the Senate Armed Services Committee,” March 16,
2023, https://www.africom.mil/document/35173/africom-cleared-fy24-sasc-posture-hearing-16-mar-2023pdf.
61 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
62 U.S. Navy, “Installation Information,” https://cnreurafcent.cnic.navy.mil/Installations/Camp-Lemonnier-Djibouti/.
Rion Codrington, “Partner Appreciation Day Celebrates 21 Days of Partnership at Camp Lemonnier,” U.S. Navy,
November 8, 2023, https://cnreurafcent.cnic.navy.mil/Installations/Camp-Lemonnier-Djibouti/News/Article/3587466/
partner-appreciation-day-celebrates-21-years-of-partnership-at-camp-lemonnier/. AFRICOM has also confirmed this
figure.
63 AFRICOM, “About the Command,” https://www.africom.mil/about-the-command.
64 AFRICOM, Statement of General Michael E. Langley before the Senate Armed Services Committee,” March 7,
2024, https://www.africom.mil/document/35430/usafricom-fy25-posture-statement-iso-sasc-hearing-7-mar-24pdf.
65 Michael Phillips, “U.S. Seeks Drone Bases in Coastal West Africa to Stem Islamist Advance,” The Wall Street
Journal, January 3, 2024, https://www.wsj.com/world/africa/u-s-seeks-drone-bases-in-coastal-west-africa-to-stem-
islamist-advance-21282861.
66 DOD, “Joint Statement from the U.S. Department of Defense and the Department of National Defense of the
Republic of Niger,” May 19, 2024, https://www.defense.gov/News/Releases/Release/Article/3780392/joint-statement-
from-the-us-department-of-defense-and-the-department-of-nationa.
Congressional Research Service

14

U.S. Overseas Basing: Background and Issues for Congress

Figure 5. U.S. Overseas Bases in Africa

Source: CRS analysis of unclassified U.S. government documentation (including DOD budget documents, Base
Structure Reports, official unit/installation webpages, press releases, Department of State documents,
congressional testimony, and information provided by executive branch officials to CRS).
Notes: The “Persistent” label describes a site that has been used consistently by DOD for at least 15 years and
at which DOD exercises some degree of operational control.

Congressional Research Service

15

link to page 35 U.S. Overseas Basing: Background and Issues for Congress

Central/South America and the Caribbean
For the purposes of this report, Central/South America and the Caribbean correspond with the
U.S. Southern Command (SOUTHCOM) AOR, with one exception (the Bahamas—which hosts
the U.S. Navy’s Atlantic Undersea Test and Evaluation Center—is technically in the U.S.
Northern Command AOR). CRS identified three persistent bases and three other military sites to
which DOD has access in the region. As of March 2024, approximately 1,650 active-duty
servicemembers were permanently assigned to overseas bases in Latin America and the
Caribbean, with the largest number assigned to Cuba (616) and Honduras (365).67 SOUTHCOM
is headquartered in Doral, Florida.68
Overseas basing in Central/South America and the Caribbean appears to mainly support
counternarcotics operations, as well as some logistical and Research, Development, Test and
Evaluation (RDT&E) activities.69 In her 2024 Posture Statement before the House Armed
Services Committee, the SOUTHCOM commander described the expansion of PRC and Russian
influence and the activities of transnational criminal organizations as major regional threats to
U.S. security.70

67 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
68 SOUTHCOM, “About Us,” https://www.southcom.mil/About/.
69 See the “Latin America and the Caribbean” section of Appendix A.
70 U.S. Congress, House Committee on Armed Services, Statement of General Laura Richardson, United States Army,
U.S. Southern Command Posture Statement, 118th Cong., 1st sess., March 8, 2023, p. 3 available at
https://www.southcom.mil/Portals/7/Documents/Posture%20Statements/2023%20SOUTHCOM%20Posture%20Statem
ent%20FINAL.pdf?ver=rxp7ePMgfX1aZVKA6dl3ww%3d%3d.
Congressional Research Service

16

U.S. Overseas Basing: Background and Issues for Congress

Figure 6. U.S. Overseas Bases in Central/South America and the Caribbean

Source: CRS analysis of unclassified U.S. government documentation (including DOD budget documents, Base
Structure Reports, official unit/installation webpages, press releases, Department of State documents,
congressional testimony, and information provided by executive branch officials to CRS).
Notes: The “Persistent” label describes a site that has been used consistently by DOD for at least 15 years and
at which DOD exercises some degree of operational control. Acronyms: CSL=Cooperative Security Location.
Congressional Research Service

17

U.S. Overseas Basing: Background and Issues for Congress

Authorities and Management
Treaties and International Agreements
To acquire, lease, or otherwise obtain access to land and facilities for the purpose of overseas
basing, the United States enters into diplomatic arrangements with foreign governments.
Generally speaking, such arrangements take the form of bilateral agreements concluded between
the executive branch and host-nation governments. These agreements may be referred to by a
number of different names, including Status of Forces Agreements (SOFAs), Defense
Cooperation Agreements (DCAs), Visiting Forces Agreements (VFAs), or Memoranda of
Understanding (MOUs), and their scopes and provisions may vary widely. In some cases, the
terms of such agreements—or even their existence—may not be public.
International agreements addressing basing rights are also typically separate from (though aligned
with or governed by) any treaty that may exist between the United States and the country in
question.71 Such agreements may also address related issues such as legal jurisdiction over U.S.
personnel, tax and customs exemptions, or other issues. In addition to its bilateral basing
agreements, the United States is party to a multilateral SOFA that applies to all members of the
North Atlantic Treaty Organization (NATO).72
The specific terms negotiated to govern land and infrastructure usage at overseas bases may vary
by location. However, some practices and procedures are generally observed. According to DOD:
The Department uses land, buildings, and other overseas facilities obtained through various
international treaties and agreements negotiated by the Department of State. The
Department purchases capital assets overseas with appropriated funds; however, the host
country retains title to the land and capital improvements. Treaty terms generally allow the
Department continued use of these properties until the treaties expire. In the event treaties
or other agreements are terminated, use of the foreign bases is prohibited and losses are
recorded for the value of any irretrievable capital assets. The settlement due to the United
States or host nation is negotiated and takes into account the value of capital investments
and may be offset by environmental cleanup costs, if applicable.73
Relevant Statutory Authorities
Title 10, Chapter 159 of the United States Code (U.S.C.) governs DOD’s acquisition, use, and
disposal of real property, including overseas bases.74 Relevant portions of this chapter include
provisions authorizing the Secretary of Defense to lease land and structures in foreign countries
(10 U.S.C. §2675) and requiring the Secretary of Defense to provide information to Congress
regarding overseas base closures and realignments, as well as the status of overseas bases (10
U.S.C. §2687a).75 In addition, 10 U.S.C. §2350k authorizes the Secretary of Defense to “accept

71 For example, the U.S.-Japan SOFA states that it is enacted “pursuant to Article VI of the Treaty of Mutual
Cooperation and Security between the United States of America and Japan.” “Agreement… Regarding Facilities and
Areas and the Status of United States Armed Forces in Japan,” 1960, available online via U.S. Army Japan at
https://www.usarj.army.mil/Portals/33/cmdstaffs/sja/doc/sofa_201601.pdf.
72 The text of this SOFA is available at https://www.nato.int/cps/en/natohq/official_texts_17265.htm.
73 DOD, FY2023 Agency Financial Report, November 2023, p. 145, https://comptroller.defense.gov/Portals/45/
Documents/afr/fy2023/DoD_FY23_Agency_Financial_Report.pdf.
74 10 U.S.C. §2661 et seq.
75 10 U.S.C. §2687a required DOD to provide an annual report to Congress detailing the status of overseas bases. Per
Sec. 1061 of the FY2017 National Defense Authorization Act (P.L. 114-328), the requirement for DOD to submit this
report ended on December 31, 2021.
Congressional Research Service

18

link to page 30 U.S. Overseas Basing: Background and Issues for Congress

contributions from any nation because of or in support of the relocation of elements of the armed
forces from or to any location within that nation.” These contributions may be used to pay
numerous overseas basing costs, including those related to design and construction services,
communications services, and the rental of office space.76 Finally, 10 U.S.C. §2721 requires the
Secretary of Defense to maintain records of, inter alia, the department’s fixed property and
installations “on both a quantitative and a monetary basis.”77
DOD Policy and Organizations
To manage its overseas bases, DOD has promulgated several issuances to establish policy and
assign responsibilities. DOD Instruction 3000.12 establishes a Global Posture Executive Council
(GPEC) to oversee global defense posture (which consists of the placement and organization of
overseas bases, together with the positioning of forces and the structuring of international security
agreements).78 Pursuant to this instruction, several DOD positions are responsible for broad
aspects of overseas basing, including:
• The Under Secretary of Defense for Policy (USD [P]). USD (P) “establishes
policy and overall guidance for the governance of global defense posture.”79
• The Assistant Secretary of Defense for Strategy, Plans and Capabilities (ASD
[SPC]) and the Director, Joint Staff (DJS). The ASD (SPC) and the DJS co-
chair the GPEC and provide oversight, policy guidance, and assistance on
posture matters.80
• The Secretaries of the Military Departments and Military Service Chiefs.
The Secretaries and Service Chiefs review combatant commander posture plans,
support posture planning by requiring relevant cost data and estimates, and
provide base operations support and management functions for enduring
locations assigned to their Service(s).81
• The Combatant Commanders (CCDRS). The CCDRS evaluate the adequacy
of current posture to support their campaign plans and associated objectives,
develop a theater or functional posture plan, and coordinate requirements with
other stakeholders.82
The GPEC also includes representation from numerous other DOD and U.S. government
organizations.83

76 10 U.S.C. §2350k. Refer to the “Burden Sharing” subsection of this report for further discussion of this issue.
77 10 U.S.C. §2721. DOD’s annual Base Structure Report is prepared in accordance with the requirements of this
statute.
78 DOD, DOD Instruction 3000.12 (“Management of U.S. Global Defense Posture”), May 8, 2017, p. 6,
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/300012p.pdf.
79 Ibid.
80 Ibid.
81 Ibid.
82 In addition to the DOD officials noted above, the Under Secretary of Defense for Acquisition and Sustainment (USD
(A&S)) exercises overall responsibility and oversight of DoD real property, including the maintenance of a real
property inventory. Within the office of the USD (A&S), the Office of the Assistant Secretary of Defense for Energy,
Installations, and Environment produces the annual Base Structure Report. See DOD, “DOD Instruction 4165.14 (Real
Property Inventory and Reporting),” September 8, 2023, pp. 4-5, https://www.esd.whs.mil/Portals/54/Documents/DD/
issuances/dodi/416514p.pdf?ver=201.
83 These include: the Under Secretary of Defense for Policy (USD [P]); the Under Secretary of Defense for Acquisition
(continued...)
Congressional Research Service

19

U.S. Overseas Basing: Background and Issues for Congress

In addition to DODI 3000.12, DOD Directive 3000.10 (“Contingency Basing Outside the United
States”) establishes policy and assigns responsibilities specifically for overseas contingency
basing.84
On a day-to-day basis, each military department (MILDEP) manages its overseas bases through
its own organizational structures, policies, and programs.85 From a regional and joint perspective,
the six geographically organized COCOMs provide oversight and theater-level direction of the
strategic and operational dimensions of DOD’s overseas basing posture.
Issues for Congress
Resourcing Overseas Basing
Congress’s most direct role in overseas basing is to consider whether or not to make funds
available to establish and maintain military bases. Congress appropriates funds to military
construction (MILCON) accounts to pay for the construction or expansion of base facilities and
certain operation and maintenance (O&M) accounts to pay for base operations, maintenance, and
related support activities.86 Congress also funds appropriations accounts that support other aspects
of DOD’s global defense posture (e.g., overseas deployments) that may be considered part of
overseas basing. Congress faces questions that include: (1) whether to appropriate funds for
overseas basing-related activities (and, if so, how much); and (2) whether DOD’s execution of
overseas basing-related appropriations meets congressional intent.
Total Overseas Basing Costs
Other than for military construction projects, DOD’s budget documents do not typically break
down spending by geographical location. As a result, it can be difficult to accurately determine
the total costs of overseas basing, or identify costs by region or site. There are also numerous
ways to define the costs of overseas basing, each of which could yield different figures. For
example, one definition could include only spending associated with the real property and
physical infrastructure (e.g., buildings, structures) occupied by overseas bases. Another could
include spending associated with permanently stationing DOD servicemembers, weapons
systems, and other assets overseas.87 A third could include the costs of rotational deployments,

and Sustainment (USD [A&S]); the Director of Cost Assessment and Program Evaluation (OSD [CAPE]); the Under
Secretary of Defense, Comptroller/Chief Financial Officer, Department of Defense (OUSD[C]/CFO; the Under
Secretary of Defense for Personnel and Readiness (OUSD [P&R]); the Department of State; and the National Security
Council. DOD Instruction 3000.12 (“Management of U.S. Global Defense Posture”), DOD, May 8, 2017, pp. 6-7.
84 Organizations with responsibilities relating to overseas contingency basing under DOD Directive 3000.10 include
those identified in DOD Instruction 3000.12, plus the Assistant Secretary of Defense for Sustainment, the Under
Secretary of Defense for Intelligence and Security, and the DOD Chief Information Officer. DOD Directive 3000.10
(“Contingency Basing Outside the United States”), DOD, August 27, 2021, https://www.esd.whs.mil/Portals/54/
Documents/DD/issuances/dodd/300010p.pdf?ver=2017-08-18-132434-003.
85 For more information on the general management of military bases, see CRS In Focus IF11263, Defense Primer:
Military Installations Management.
86 For more information on MILCON appropriations, see CRS Report R44710, Military Construction: Authorities and
Processes.
87 Including costs related to the personnel or weapons systems that DOD bases overseas in an estimate of total costs for
overseas bases is subject to debate because moving such personnel or weapons systems back to the Continental United
States (CONUS) would not necessarily eliminate those costs. Attempts to determine a marginal increased cost for
basing personnel and weapons overseas are subject to numerous assumptions. See for example, RAND Corporation, A
Cost Analysis of the U.S. Air Force Overseas Posture, 2013, https://www.rand.org/pubs/research_reports/RR150.html.
Congressional Research Service

20

link to page 26 link to page 27 link to page 27 U.S. Overseas Basing: Background and Issues for Congress

exercises, and similar activities conducted at overseas bases. Because MILCON and certain O&M
accounts (i.e., the Base Operations Support, or BOS, and Facilities Sustainment, Restoration, and
Modernization, or FSRM, subactivity groups) are common to all three definitions, these
appropriations are discussed in more detail in the “MILCON ” and “Operation & Maintenance
(O&M) ” sections of this report.
To estimate total overseas basing-related MILCON spending for FY2023, CRS reviewed DOD’s
FY2024 “Military Construction, Family Housing, and Base Realignment and Closure Program
(C-1)” budget submission. The total obligation authority enacted for FY2023 for MILCON
projects associated with combatant commands outside the continental United States (OCONUS)
was $5.355 billion.88
In FY2023, DOD provided two different estimates of non-MILCON overseas basing costs as part
of its annual budget submission. The first is the “overseas cost summary” which “identifies the
amounts necessary for payment of all personnel, operations, maintenance, facilities, and support
costs for all [DOD] overseas military units and the costs of supporting all dependents who
accompany DoD personnel outside of the United States.”89 This estimate—which includes some
funding for procurement and research and development—puts the total cost for overseas
operations activities at $27.8 billion.90
In the same document, DOD provided an estimate of $31.7 billion for enacted appropriations to
support overseas operations in FY2023.91
Although the figures reported by DOD may serve as a useful indicator, they may not include all
of the non-MILCON spending associated with overseas basing, as they may exclude costs related
to contingency operations, rotational deployments or training exercises involving units ordinarily
based in the United States.
Independent researchers have also provided alternative estimates for the total cost of U.S.
overseas basing. One 2021 study by the Quincy Institute for Responsible Statecraft estimated the
total cost to be $55 billion annually.92 A RAND Corporation report from 2013 analyzed the Air
Force’s overseas operations and concluded that the costs to maintain the Air Force's overseas

88 In this instance, the data for overseas bases includes Guam and Hawaii, which are geographically within the
INDOPACOM AOR. Office of the Under Secretary of Defense (Comptroller/Chief Financial Officer), Military
Construction, Budget Estimates for Fiscal Years 2023, (C-1), https://comptroller.defense.gov/Budget-Materials/
Budget2025/, provided the source for the analysis.
89 Office of the Under Secretary of Defense (Comptroller/Chief Financial Officer), Defense Operations and
Maintenance Overview Book, Fiscal Year 2024 Budget Estimates, Overseas Cost Summary, May 2023, p. 191,
https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2024/FY2024_OM_Overview.pdf
90 According to DOD, this estimate aims to capture “the amounts necessary for payment of all personnel, operations,
maintenance, facilities, and support costs for all overseas military units and the costs of supporting all dependents who
accompany DOD personnel outside of the United States.” Office of the Under Secretary of Defense (Comptroller/Chief
Financial Officer), Defense Operations and Maintenance Overview Book, Fiscal Year 2024 Budget Estimates,
Overseas Cost Summary, May 2023, p. 191, https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2024/
FY2024_OM_Overview.pdf.
91 Office of the Under Secretary of Defense (Comptroller/Chief Financial Officer), Defense Operations and
Maintenance Overview Book, Fiscal Year 2024 Budget Estimates, Overseas Cost Summary, May 2023, p. 325-326,
https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2024/FY2024_OM_Overview.pdf.
92 Quincy Institute for Responsible Statecraft, “Drawdown: Improving U.S. and Global Security Through Base
Closures Abroad,” September 24, 2021, p. 3, https://quincyinst.org/wp-content/uploads/2021/09/quincy-brief-no.-16-
sept-2021-vine-1.pdf.
Congressional Research Service

21

U.S. Overseas Basing: Background and Issues for Congress

force structures and installations overseas rather than in the United States was roughly $3.4
billion, which amounted to about 2% of the Air Force's total budget at the time of the study.93
Some of DOD’s overseas basing costs may be defrayed by financial or in-kind contributions from
foreign governments. For further discussion, refer to this report’s “Burden Sharing” section
below.
MILCON Appropriations
MILCON appropriations fund the planning, design, and building of physical infrastructure at
DOD installations.94 In FY2023, Congress appropriated a total of $13.593 billion for specific
MILCON projects worldwide.95 Of that total, $5.355 billion—or 39%—went to locations in
overseas combatant commands. Congress may consider whether this total is appropriate to meet
U.S. strategic and operational objectives; depending on its assessment, Congress may consider
increasing, decreasing, or keeping constant annual MILCON appropriations.
Aside from the question of how much total funding to appropriate for overseas MILCON
projects, Congress may also consider where and how MILCON funds are spent. As Figure 3
shows, the regional distribution of MILCON funding has varied over the past 15 years. The
proportion of spending in the CENTCOM AOR—which accounted for a plurality of overseas
MILCON projects by financial value for several years during the late 2000s and early 2010s—has
decreased considerably, for instance, while projects in the INDOPACOM AOR have accounted
for the majority of overseas MILCON spending for the past four fiscal years.96 This change likely
reflects strategic developments; as DOD’s focus has shifted from the Global War on Terror to
great power competition, the allocation of MILCON funds has changed to reflect the increased
importance of Europe and the Indo-Pacific vis-à-vis the Middle East. Congress may consider
whether the current distribution of MILCON funds adequately reflects the balance of its regional
priorities and may determine whether or not to modify the geographical or functional allocation
of such appropriations.

93 RAND Corporation, A Cost Analysis of the U.S. Air Force Overseas Posture, 2013, https://www.rand.org/pubs/
research_reports/RR150.html.
94 For more information on MILCON appropriations generally, see CRS Report R44710, Military Construction:
Authorities and Processes.
95 The $13.593 billion figure here is based on a CRS analysis of DOD C-1 documents and includes all military
construction projects for which funding was appropriated for FY2023 and for which DOD recorded a specific location
for the project; it does not include accounts such as unspecified minor military construction, planning and design, Base
Realignment and Closure (BRAC) activities, family housing operations, family housing improvement funds and the
NATO Security Investment Program. In this instance, the data for overseas bases includes Guam and Hawaii, which are
geographically within the INDOPACOM AOR. Office of the Under Secretary of Defense (Comptroller/Chief Financial
Officer), Military Construction, Budget Estimates for Fiscal Years 2023, (C-1), https://comptroller.defense.gov/Budget-
Materials/Budget2025, provided the source for the analysis.
96 Because the INDOPACOM AOR includes Hawaii, Guam, and other U.S. territories, not all INDOPACOM MILCON
spending is associated with overseas basing.
Congressional Research Service

22

U.S. Overseas Basing: Background and Issues for Congress

Figure 7. DOD Military Construction Spending by Region, FY2007-FY2023
Total Obligational Authority by COCOM AOR

Source: CRS analysis of DOD Under Secretary of Defense (Comptrol er) Military Construction, Family Housing
and Base Realignment and Closure Program (C-1) documents, FY2015-FY2023,
https://comptrol er.defense.gov/Budget-Materials/.
Notes: This figure excludes MILCON accounts that are not associated with specific locations in DOD budget
documents (e.g., DOD-wide, Planning and Design accounts, Family Housing Operations and Maintenance, Base
Realignment and Closure Account, Family Housing Improvement Fund). Data also excludes MILCON projects in
the continental United States/elsewhere in the NORTHCOM AOR.
Operation & Maintenance (O&M) Appropriations
Two subactivity groups (SAGs) within the operation and maintenance (O&M) appropriation
directly fund support and maintenance of military bases, including those overseas: Base
Operations Support (BOS) and Facilities Sustainment, Restoration, and Management (FSRM).
Unlike MILCON, these elements of O&M spending are not typically disaggregated by location or
installation; CRS is therefore unable to perform a geographic analysis of Base Operations Support
or Facilities Sustainment, Restoration, and Modernization spending.
The FSRM SAGs support activities such as major repairs to buildings and structures, the
restoration of damaged facilities, and limited facility alterations. In FY2023, Congress
appropriated approximately $17.419 billion for FSRM across DOD, with the active-component
Army (approximately $5.147 billion), the active-component Air Force (approximately $4.391
billion), the active-component Navy (approximately $3.956 billion), and the active-component
Marine Corps ($1.342 billion) receiving the largest amounts, respectively.97 These FSRM figures
include domestic and overseas costs.98

97 The FSRM total of $17.419 also include accounts for reserve components; the Joint Explanatory Statement for the
Department of Defense Appropriations Act, 2023, provided the source for this analysis, available at
https://www.appropriations.senate.gov/imo/media/doc/Division%20C%20-
%20Defense%20Statement%20FY23.pdf#PAGE=50.
98 DOD’s budget documentation does not distinguish between overseas FSRM funding allocated to domestic and
overseas locations.
Congressional Research Service

23

link to page 22 U.S. Overseas Basing: Background and Issues for Congress

The BOS SAGs fund “installation services,” including facilities operations (e.g., utilities,
engineering services), logistics operations (e.g., food services, vehicle management), community
services (e.g., morale, welfare, and recreation programs), security services (e.g., installation law
enforcement, physical security), information technology services (e.g., telephones, network
services), and related activities.99
Congress may consider whether these totals are adequate to meet its basing objectives and
priorities, and adjust the level of annual appropriations as necessary. For example, if Congress
assesses that the tempo of overseas base operations is increasing, it may decide to increase
appropriations for BOS or FSRM activities; conversely, if Congress determines that there is less
need for such operations, it may hold these appropriations constant or decrease them.
Additionally, if Congress determines it lacks sufficient information about where these O&M
funds are actually being spent, it may require DOD to provide more information as to the
geographic distribution of overseas basing-related O&M spending.
Managing Relations with Host Nations
The strategic value of an overseas base depends in large part on good U.S. relations with the
base’s host nation—that is, the nation whose territory the base occupies. With certain limited
exceptions, the United States does not typically maintain overseas bases without the agreement of
the host nation (of the areas covered by this report, only sites in Syria and Guantanamo Bay in
Cuba are used without host-nation consent).100
Congress faces several related questions, such as whether or not the executive branch is
developing and maintaining relations with host nations that adequately support U.S. national
strategy and congressional policy priorities; how the presence and operation of U.S. forces may
affect regional security dynamics; how the behavior of adversaries may affect the security of U.S.
servicemembers and partner forces; and what the costs and consequences of alternative
approaches may be.
Negotiating Basing Rights
As described in the “Authorities and Management” section of this report, the United States relies
on a variety of diplomatic understandings—mainly, but not exclusively, bilateral executive
agreements—to establish and govern overseas basing rights.
As a result, the executive branch—especially DOD and the Department of State—is mainly
responsible for negotiating the terms and conditions of U.S. overseas basing rights. However,
Congress may exercise oversight over the terms and implementation of these executive
agreements by requiring reports, holding hearings, expressing the sense of Congress, or issuing
direction to DOD through legislation. Additionally, Congress may choose to legislate a statutory
role for itself in the negotiation or approval of basing agreements, if Members determine that
congressional priorities are not adequately reflected in the executive branch’s handling of such

99 Each of the MILDEPs manages its own Base Operations Support SAG; for an example, see “FY2024 Budget
Estimates, O&M, Army, Vol. I,” Department of the Army, March 2023, pp. 202-203, https://www.asafm.army.mil/
Portals/72/Documents/BudgetMaterial/2024/Base%20Budget/Operation%20and%20Maintenance/
Regular%20Army%20Operation%20and%20Maintenance%20Volume%201.pdf.
100 Both the Syrian and Cuban governments consider the U.S. military presence in their respective countries to
contravene their sovereignty and violate international law. See “We Demand Immediate and Unconditional Withdrawal
of Foreign Forces from Syrian Territory,” Syrian Arab News Agency, December 22, 2017, https://sana.sy/en/
?p=122073, and CRS Report R44137, Naval Station Guantanamo Bay: History and Legal Issues Regarding Its Lease
Agreements.
Congressional Research Service

24

U.S. Overseas Basing: Background and Issues for Congress

relations (for example, Congress could require notification or approval before the conclusion of
any new basing agreements or it could link U.S. financial expenditures on basing in certain
countries to specific burden sharing, force protection, or other considerations). For basing
arrangements that require congressional action or approval (for example, those established by
treaties, or congressionally enacted agreements like the Compacts of Free Association), Congress
may consider which kinds of terms and conditions are most advantageous to the national interest.
Reliable Access and Political Risk
Another issue Congress may consider is reliability of U.S. access to overseas bases, which may
be understood as a function of political risk.
Because nearly all overseas bases are ultimately subject to foreign sovereignty, DOD’s ability to
use these locations may be affected by political developments beyond U.S. control.101 Instances of
host nations altering the terms of—or outright revoking—U.S. basing rights have occurred
several times in recent history, and can create strategic and operational problems for military
planners. The presence of U.S. forces in a country may be the subject of political controversy, and
ensuing disputes may lead to abrupt and substantial policy or security changes.
In some cases, host-nation governments have unexpectedly decided to expel U.S. forces (as in
France during the mid-1960s, when French president Charles de Gaulle informed the United
States that existing basing agreements between the two countries no longer obtained, ending two
decades of U.S. military presence).102 On other occasions, host-nation governments have moved
to restrict the ways in which DOD may use bases located in their territories (for example, in 2003
the Turkish government blocked the U.S. military from using Incirlik Air Base for combat
operations against Iraq).103 Another possibility is that a new government may come to power and
radically change its country’s approach to U.S. basing (as happened recently in Niger, when—
following a 2023 coup d’état—the new military junta unilaterally cancelled the existing SOFA
with the United States, compelling the withdrawal of U.S. forces and the abandonment of two
bases).104
Congress may also consider the question of access during periods of protracted or intense
conflict. Host nations may be unwilling to allow the United States to use bases in their territories,
for fear it could expose them to attack or involve them in a war they would rather avoid.
Depending on the nature of the conflict, it is possible that even treaty allies may decide to restrict
or prohibit the use of their territories by the U.S. military. For example, senior officials in the
Philippines—a U.S. treaty ally that hosts bases seen by many analysts as relevant to a potential

101 There are a few bases over which the United States may be said to exercise a kind of de facto sovereignty, since it
operates them without the consent of the country in whose legal territory they are located (e.g., the base at Al Tanf in
Syria and Guantanamo Bay in Cuba). For academic treatments of the complex relationship between sovereignty and
overseas basing, see Sebastian Schmidt, Armed Guests (2020) and Alexander Cooley and Hendrik Spruyt, Contracting
States: Sovereign Transfers in International Relations (Princeton: Princeton University Press, 2009).
102 This occurred in 1966, as part of France’s withdrawal from NATO’s integrated command structure. See Eric Stein
and Dominique Carreau. “Law and Peaceful Change in a Subsystem: ‘Withdrawal’ of France from the North Atlantic
Treaty Organization.” The American Journal of International Law 62, no. 3 (1968): 577–640, https://doi.org/10.2307/
2197283. See also Jean Lacouture, De Gaulle: The Ruler, 1945-1970 (New York: Norton & Company, 1991), p. 519.
103 In February 2024, the government of Iraq was reportedly considering altering or revoking U.S. basing rights in
response to U.S. strikes against militias operating in the country. See CRS Insight IN12309, Iraq: Attacks and U.S.
Strikes Reopen Discussion of U.S. Military Presence. See also Guy Chazan, “As U.S.-Turkish Relations Fray, Historic
Base Is on the Sidelines,” The Wall Street Journal, April 2, 2003.
104 For more information, refer to CRS In Focus IF12464, Niger, by Alexis Arieff; see also Eric Schmitt, “U.S. and
Niger Announce Withdrawal of American Personnel by September,” The New York Times, May 19, 2024,
https://www.nytimes.com/2024/05/19/us/politics/us-niger-military-withdrawal.html.
Congressional Research Service

25

U.S. Overseas Basing: Background and Issues for Congress

U.S.-China conflict—have stated that, in the event of a regional war, their government may bar
U.S. forces from using Philippine territory to conduct or support combat operations against third
parties.105
Congress may consider the degree to which the United States can depend on host nations—
particularly countries with histories of instability or anti-American political traditions—to grant
or maintain basing rights on sufficiently favorable terms. Congress may also consider whether or
not DOD adequately accounts for this kind of political risk in its strategic and operational
planning. If Congress identifies issues with DOD’s approach, it could require new plans,
strategies, or reports to address these risks. If there are particular countries of concern, Congress
could also prohibit the development of new basing arrangements with these countries, or
introduce specific requirements to govern basing in these locations.
Burden Sharing
Another issue is the degree to which a host nation may contribute to the upkeep and support of
U.S. forces and facilities at bases in its territory (often referred to as burden sharing). The
question of whether host nations are paying enough to support U.S. basing has been a contentious
political issue since the early Cold War. Some critics and policymakers have alleged that host-
nation governments contribute less than they should to defray the costs of America’s military
presence in their countries, especially considering that: (1) some host nations (such as Germany,
Japan, and South Korea) are high-income countries; and (2) U.S. basing provides security and
further economic benefits.106 Others have argued that host nations generally contribute an
appropriate amount to support U.S. basing and that the United States benefits as much as host
nations from its global defense posture.107
DOD annually reports at least some of the burden sharing contributions it receives from host
nations. According to the most recent report, in FY2023, the United States received a total of
$714.2 million in burden sharing contributions from five countries (Kuwait, Japan, South Korea,
Saudi Arabia, and Poland).108
Despite this information, as noted above, the structure of DOD’s budget presents difficulty in
determining the costs associated with overseas basing. CRS is unable to conclusively determine
how much of DOD’s total overseas basing costs are covered by host-nation contributions. The
Government Accountability Office (GAO) recently attempted to evaluate burden sharing for
major U.S. allies in a 2021 report examining, inter alia, the contributions of the Japanese and
South Korean governments to supporting the U.S. military presence in their respective countries.
GAO found that, between FY2016 and F2019, Japan and South Korea provided $12.6 billion and

105 In April 2023, for instance, Philippine President Ferdinand Marcos Jr. said that U.S. forces would be barred from
using bases in his country to undertake “offensive action.” Kristina Maralit, “Marcos rules out offensive actions from
new EDCA sites,” The Manila Times, April 11, 2023. See also discussion in CRS Report R47589, U.S. Defense
Infrastructure in the Indo-Pacific: Background and Issues for Congress, pp. 22-23. Some analysts have raised similar
questions about South Korea and Japan—see, for example, Kiyoshi Sugawa, “Should Japan Defend Taiwan?”,
Responsible Statecraft, May 2023, https://responsiblestatecraft.org/2023/05/02/should-japan-defend-taiwan/.
106 For an example of this argument, see Doug Bandow, “750 Bases in 80 Countries Is Too Many for Any Nation: Time
for the US to Bring Its Troops Home,” Cato Institute, October 4, 2021, https://www.cato.org/commentary/750-bases-
80-countries-too-many-any-nation-time-us-bring-its-troops-home.
107 For an example of this argument, see Rachel S. Cohen, “Why Overseas Military Bases Continue to Make Sense,”
War on the Rocks, January 14, 2021, https://warontherocks.com/2021/01/why-overseas-military-bases-continue-to-
make-sense-for-the-united-states/.
108 DOD, “Report on Burden Sharing Contributions,” December 2023. This report was prepared pursuant to the terms
of 10 U.S.C. §2350k(j) and is on file with the authors.
Congressional Research Service

26

U.S. Overseas Basing: Background and Issues for Congress

$5.8 billion, respectively, in “direct financial support” to pay costs—such as “labor, construction,
and utilities”—associated with U.S. overseas basing.109 In the Japanese case, host-nation
contributions amounted to 60.2% of the value of DOD obligations associated with the U.S.
military presence over the same period. In the South Korean case, host-nation contributions
amounted to 43.3% of the value of DOD obligations associated with the U.S. military presence
over the same period.110 According to media reports, the government of Germany—which hosts
the second largest number of permanently-assigned U.S. servicemembers, behind Japan—
reported contributing $270 million to U.S. basing costs between 2012 and 2019.111 As another
example, Qatar is reportedly making investments in DOD’s Al Udeid Air Base to support the
continuation of the U.S. military presence there.112
If Congress is concerned that the current degree of burden sharing is insufficient, a number of
options are available. Congress could seek more information on foreign contributions to U.S.
basing costs by requiring DOD to provide data on such contributions, commissioning
independent reports, or holding hearings. If Congress determines that host nations are not paying
enough, it could condition appropriations for certain overseas basing-related expenditures on
relevant host nation(s) meeting certain contribution thresholds, require the revision of existing
basing arrangements, or prohibit DOD from basing forces in countries that fail to contribute
sufficiently to U.S. basing costs.
Aligning Overseas Basing with Strategic and Operational Priorities
Although the executive branch has long exercised the lead role in determining national military
strategy and managing the U.S. military’s overseas basing posture, Congress may shape executive
branch decision-making and exercise oversight in a number of ways. It may assess whether the
placement and organization of overseas bases adequately supports U.S. interests and strategic
goals, for instance, and consider whether current posture meets the requirements of new
operational concepts, weapons systems, or other warfighting developments.
Overseas Basing and National Strategy
Since the early days of the Cold War, overseas basing has played a significant role in national
strategy.113 Its principal contribution has been to enable the forward presence (sometimes also
referred to as “forward deployment” or “forward posture”) of U.S. forces, which DOD officials
have claimed deters potential adversaries from attacking the United States and its allies and
partners.114 In addition to enabling military operations, overseas bases may signal that the U.S.

109 Government Accountability Office, Burden Sharing: Benefits and Costs Associated with the U.S. Military Presence
in Japan and South Korea, GAO-21-270, March 17, 2021, https://www.gao.gov/products/gao-21-270.
110 GAO calculated the total value of such DOD obligations to be $20.9 billion, in the case of Japan, and $13.4 billion,
in the case of South Korea. To arrive at these figures, GAO compiled appropriations from relevant military personnel,
O&M, and MILCON accounts. For more information on GAO’s methodology, see ibid., pp. 42-46.
111 Chase Winter, “Germany Spends Millions on U.S. Military Bases,” Deutsche Welle, August 21, 2019,
https://www.dw.com/en/germany-spends-millions-of-euros-on-us-military-bases/a-50106376.
112 For more information, see CRS Report R47467, Qatar: Issues for the 118th Congress, by Christopher M.
Blanchard, pp. 5-6.
113 See Townsend Hoopes, “Overseas Bases in American Strategy,” Foreign Affairs, October 1958, pp. 69-82,
https://www.jstor.org/stable/20029332.
114 The deterrence of adversary attacks has been a consistent goal of U.S. strategy; of the four “defense priorities”
identified by the 2022 National Defense Strategy, two (“deterring strategic attacks against the United States, Allies, and
partners” and “deterring aggression, while being prepared to prevail in conflict when necessary”) relate to deterrence.
(continued...)
Congressional Research Service

27

U.S. Overseas Basing: Background and Issues for Congress

government views particular areas as important to the national interest, as well as communicate
U.S. commitment to the defense and support of regional allies and partners. Overseas basing may
also entail risks to U.S. servicemembers and assets (for example, U.S. forces based in Iraq, Syria,
and Jordan have been attacked by armed groups dozens of times in 2023 and 2024).115
Evidence for the strategic effects of DOD’s current and recent global basing posture varies. A
2013 report on overseas basing by the RAND Corporation identified three major strategic
benefits (contingency responsiveness, deterrence and assurance, and security cooperation) and
three major strategic risks (political risks, operational risks, and violent extremism risks).116
The deterrent effect of overseas basing is difficult to measure. Some researchers have claimed
that "some types of U.S. forward posture do generally have deterrent effects when deployed near
the ally or partner state to be defended,” particularly those which are relatively immobile (e.g.,
heavy ground forces).117 Other analysts have posited that “the deterrence value of overseas
military bases is frequently exaggerated,” explaining U.S. strategic successes by reference to
geopolitical developments other than the forward military presence such bases enable.118
Among those who attribute a positive strategic effect to overseas basing, some argue that the
benefits of an expansive posture outweigh both the risks and the costs. On this view, a restrained
global or regional posture could undermine DOD’s ability to project force in distant regions and
respond to potential contingencies.119 Some also claim that an insufficiently robust basing posture
will signal to potential aggressors that a particular area is unimportant to U.S. national interests—
or that U.S. commitment to regional allies and partners is tenuous or uncertain—and thus make
conflict more likely.120
Alternatively, some maintain that an overly expansive basing posture actually increases the risk of
conflict, because it creates or intensifies adversary perceptions of U.S. threats.121 This line of
argument is sometimes connected to what international relations theorists call the security
dilemma (a phenomenon in which states’ attempts to improve their security cause other states to
feel less secure and improve their own military capabilities, precipitating a cycle that can end in
armed conflict). Some proponents of this perspective claim that U.S. basing could undermine
regional or global stability by provoking rival counter-moves.122 Others have emphasized the

National Defense Strategy, November 2022, p. 7, https://media.defense.gov/2022/oct/27/2003103845/-1/-1/1/2022-
national-defense-strategy-npr-mdr.pdf.
115 For more information, see CRS Insight IN12309, Iraq: Attacks and U.S. Strikes Reopen Discussion of U.S. Military
Presence, by Christopher M. Blanchard and CRS In Focus IF11930, Syria and U.S. Policy, by Christopher M.
Blanchard.
116 Michael J. Lostumbo et al. Overseas Basing of U.S. Military Forces, RAND Corporation, 2013,
https://www.rand.org/pubs/research_reports/RR201.html.
117 Bryan Frederick et al., Understanding the Deterrent Impact of U.S. Overseas Forces, RAND Corporation, 2020, pp.
xiv-xv, https://www.rand.org/pubs/research_reports/RR2533.html.
118 John Glaser, “Withdrawing from Overseas Bases,” Cato Institute, July 18, 2017, https://www.jstor.org/stable/
resrep04988.
119 For an example of this argument, see Raphael S. Cohen, “Why Overseas Military Bases Continue to Make Sense for
the United States,” War on the Rocks, January 14, 2021, https://warontherocks.com/2021/01/why-overseas-military-
bases-continue-to-make-sense-for-the-united-states/.
120 Ibid.
121 For an example of this argument, see Tyler McBrien, “Why the U.S. Should Close Its Overseas Military Bases,”
Foreign Policy, May 16, 2023, https://foreignpolicy.com/2023/05/16/military-defense-overseas-bases-united-states-
force-posture/.
122 For an example of this argument, see Stephen M. Walt, “Does Anyone Still Understand the ‘Security Dilemma’?”
Foreign Policy, July 26, 2022, https://foreignpolicy.com/2022/07/26/misperception-security-dilemma-ir-theory-russia-
ukraine/.
Congressional Research Service

28

U.S. Overseas Basing: Background and Issues for Congress

costs for U.S. servicemembers, arguing that overseas basing in conflict-prone areas unnecessarily
exposes DOD servicemembers to danger without meaningfully contributing to national
security.123
Congress may assess the strategic consequences of DOD’s current overseas basing posture, and
consider whether or not modifications to that posture—such as increasing or reducing the number
of overseas bases—would advance U.S. interests.
Overseas Basing and Distributed Operational Concepts
In addition to broader strategic considerations, Congress may also consider the degree to which
overseas basing posture aligns with DOD’s own warfighting plans and requirements. Over the
past five years, the Air Force, Army, Navy, and Marine Corps have all developed concepts for
more distributed and diversified combat and logistical operations. The Air Force’s Agile Combat
Employment (ACE), the Army’s Multi-Domain Operations (MDO), the Navy’s Distributed
Maritime Operations (DMO), and the Marine Corps’ Expeditionary Advanced Basing Operations
(EABO) all represent attempts to reduce the vulnerability of air, naval, and ground forces and
increase their effectiveness against an adversary able to credibly disrupt, contest, or deny U.S.
control of the battlespace.124 The services’ new concepts break from previous planning paradigms,
and their implementation may require a different approach to basing, one in which large,
permanent, and concentrated bases are supplemented by—or even replaced with—smaller,
temporary, or distributed facilities.
Of all of these operational concepts, ACE may potentially entail the most significant basing
changes. The Air Force describes ACE as a means of “shift[ing] operations from centralized
physical infrastructures to a network of smaller, dispersed locations that can complicate adversary
planning and provide more options for joint force commanders.”125 Some analysts have
characterized this as a ‘hub-and-spokes’ approach, with an enduring location (e.g., an existing
U.S. or allied airbase) serving as a hub for a number of contingency locations (e.g., civilian
airports, austere airstrips) between which aircraft can be shifted and from which sorties may be
launched. According to its proponents, ACE will thereby minimize vulnerability to kinetic attack
(particularly in regions like the Indo-Pacific and Europe, where potential adversaries possess
highly capable ballistic missile arsenals) and maximize the effectiveness of U.S. and allied
airpower.126
Although the basing implications of the Army’s MDO and the Navy’s DMO are less sweeping,
both concepts envision decreasing the concentration of logistics and supply infrastructure. As part
of MDO, the Army seeks to “disperse deployment and sustainment,” partly through “dispersed
supply nodes operated by forward presence units;” while the Navy’s vision of a larger, more
dispersed fleet operating over a wider area could increase the need for forward, distributed
logistics and maintenance sites (including what the Navy terms “distributed expeditionary shore

123 For examples of this argument in the context of Middle East basing, see Matthew Petti, “The Killing of 3 American
Troops Was an Avoidable Tragedy,” Reason, January 29, 2024, https://reason.com/2024/01/29/the-killing-of-3-
american-troops-was-an-avoidable-tragedy/; and Paul Pillar, “Bring U.S. Troops Home From Iraq and Syria Now,”
Responsible Statecraft, Jan. 29, 2024, https://responsiblestatecraft.org/us-troops-iraq-syria-jordan/.
124 For more information, see CRS In Focus IF12599, Defense Primer: Navy Distributed Maritime Operations (DMO)
Concept, by Ronald O'Rourke and CRS In Focus IF11409, Defense Primer: Army Multi-Domain Operations (MDO),
by Andrew Feickert.
125 “Agile Combat Employment,” U.S. Air Force, pp. 3-4, https://www.doctrine.af.mil/portals/61/documents/ afdn_1-
21/afdn%201-21%20ace.pdf.
126 See CRS In Focus IF12694, Defense Primer: Agile Combat Employment (ACE) Concept, by Sarah Gee and Luke A.
Nicastro.
Congressional Research Service

29

U.S. Overseas Basing: Background and Issues for Congress

infrastructure” to provide forward damage repair, mobile construction, cargo handling, and
medical services).127 From a ground-forces perspective, the Marine Corps’ EABO similarly
envisions the “employment of mobile, low-signature, persistent… naval expeditionary forces
from a series of austere, temporary locations ashore or inshore within a contested or potentially
contested maritime area.”128
The implementation of these concepts may require changes to DOD’s overseas basing posture,
resourcing, and management. They may also entail complex diplomatic negotiations with current
or potential host nations. Congress may consider the costs and benefits of a more distributed
approach to overseas basing, assess the extent to which these concepts are being implemented,
and consider whether or not changes to annual defense appropriations are necessary to
successfully execute these plans and concepts.

127 “The U.S. Army in Multi-Domain Operations 2028,” U.S. Army Training and Doctrine Command, December 6,
2018, p. 37, https://www.army.mil/article/243754/the_u_s_army_in_multi_domain_operations_2028; and “CNO
Releases Navigation Plan 2022,” U.S. Navy Press Release, July 26, 2022, p. 10, https://media.defense.gov/
2022/jul/26/2003042389/-1/-1/1/navigation%20plan%202022_signed.pdf.
128 Tentative Manual for Expeditionary Advanced Base Operations, Department of the Navy, Headquarters, U.S.
Marine Corps, February 2021, pp. 1-3 and 1-4, https://mca-marines.org/wp-content/uploads/tm-eabo-firstedition-1.pdf.
Congressional Research Service

30

U.S. Overseas Basing: Background and Issues for Congress

Appendix A. U.S. Overseas Basing by Country
This appendix provides more detailed information on U.S. overseas basing in individual
countries. The list below provides summaries of basing arrangements in 51 host nations (sorted
by region). In addition, Appendix B provides a comprehensive list of all overseas bases covered
by this report.
Indo-Pacific
U.S. overseas basing in the Indo-Pacific is established and governed by bilateral executive
agreements between the United States and regional governments, as well as congressionally-
approved Compacts of Free Association (in the cases of the Marshall Islands, Micronesia, and
Palau). Most of the U.S. servicemembers permanently assigned to this region are stationed at
persistent bases in Japan and South Korea. Over the past 15 years, DOD has established rotational
basing arrangements in Australia, the Philippines, and elsewhere.
Australia
The United States maintains Marine Rotational Force-Darwin at Royal Australian Air Force
(RAAF) Base Darwin and Robertson Barracks between April and October of each year, and
rotationally deploys combat aircraft at RAAF Base Tindal and other Australian military sites. U.S.
Virginia-class submarines are to be rotationally based near Perth beginning in the mid-to-late
2020s.129 In addition, the United States and Australia jointly operate the Naval Communication
Station Harold E. Holt and Joint Defence Facility Pine Gap sites.130
According to the Defense Manpower Data Center (DMDC), approximately 732 active-duty
servicemembers were permanently assigned to Australia as of March 2024 (this figure does not
include servicemembers on temporary duty or rotational assignments).131
British Indian Ocean Territory (Diego Garcia)
The United States maintains Naval Support Facility (NSF) Diego Garcia in the British Indian
Ocean Territory (commonly referred to as Diego Garcia), an overseas dependency of the United
Kingdom.132 NSF Diego Garcia provides logistical support for forces operating in and around the
Persian Gulf and Indian Ocean, and hosts a maritime pre-positioning squadron as well as

129 The White House, “Fact Sheet: Trilateral Australia-UK-US Partnership on Nuclear-Powered Submarines,” March
13, 2023, https://www.whitehouse.gov/briefing-room/statements-releases/2023/03/13/fact-sheet-trilateral-australia-uk-
us-partnership-on-nuclear-powered-submarines/.
130 Because these facilities perform sensitive intelligence, communications, and related functions, official sources make
scant mention of them. For recent press reporting on these sites, see Matthew Knott, “‘Seriously Disturbed’: MPs
Alarmed by Disrepair at Secretive Military Facility,” The Sydney Morning Herald, September 14, 2023,
https://www.smh.com.au/politics/federal/time-to-move-on-from-afghanistan-war-crimes-parliamentary-committee-
20230914-p5e4k6.html; and Alex Barwick, “In Alice Springs Everyone has an Opinion on the Pine Gap Spy Base, but
No-One wants to Talk about What Happens Inside,” Australian Broadcasting Corporation, May 15, 2024,
https://www.abc.net.au/news/backstory/2024-05-16/backstory-expanse-podcast-spies-in-the-outback-pine-gap-
barwick/103844652.
131 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
132 The U.S. presence at Diego Garcia dates to the late 1960s and is managed through a bilateral agreement between the
United States and the United Kingdom. For more information, see CRS Report R47589, U.S. Defense Infrastructure in
the Indo-Pacific: Background and Issues for Congress, pp. 16-17 and 43-44.
Congressional Research Service

31

U.S. Overseas Basing: Background and Issues for Congress

detachments from the U.S. Fleet and Industrial Supply Center, Air Mobility Command, Pacific
Air Force, and the 21st and 22nd Space Operations Squadrons.133
According to DMDC, approximately 223 active-duty servicemembers were permanently assigned
to Diego Garcia as of March 2024.134
Japan
Japan hosts large U.S. Army, Navy, Marine Corps, and Air Force bases, including Camp Zama,
Fleet Activities Yokosuka, Marine Corps Air Station Iwakuni, Yokota Air Base, and Misawa Air
Base.135 These sites are used to base and support a wide variety of Army ground units, Navy
vessels (including an aircraft carrier, destroyers, cruisers, and amphibious assault ships), and
Army, Navy, Marine Corps, and Air Force aircraft (including fighter, electronic attack, command
and control, tiltrotor, tanker, and airlift aircraft). DOD also uses defense infrastructure in Japan to
detect and intercept missile threats, maintain and repair surface warships and submarines, and
conduct training and exercises.136
The Japanese prefecture of Okinawa, located about 400 miles southwest of Japan’s four main
islands, hosts Army, Marine Corps, and Air Force bases, including Army Garrison Okinawa,
Marine Corps Base Camp Butler, and Kadena Air Base. These sites are used to base and support
Marine Corps ground units (including the III Marine Expeditionary Force, the Corps’ largest
combat unit stationed overseas) and Marine Corps and Air Force fighter, tilt-rotor, rotary wing,
airlift, and aerial refueling aircraft. DOD also uses Okinawa to conduct training and exercises
specific to jungle environments and to store fuel.137 DOD installations on Okinawa represent the
closest U.S.-operated bases to Taiwan and the South China Sea, both possible operational areas in
a potential conflict with the PRC. Pursuant to a bilateral agreement between the United States and
Japan, DOD has committed to relocating approximately 9,000 Marines from Okinawa to Guam
(and other locations outside Japan) beginning in 2024.138
According to DMDC, approximately 54,774 active-duty servicemembers were permanently
assigned to Japan as of March 2024.139
Republic of Korea (South Korea)
The Republic of Korea (ROK, or South Korea) hosts Army, Navy, Marine Corps, and Air Force
bases, including Camp Humphreys, Fleet Activities Chinhae, Marine Corps Installation Camp

133 “About Diego Garcia,” Commander, Navy Region Japan, https://cnrj.cnic.navy.mil/Installations/NSF-
DiegoGarcia/About/About-Diego-Garcia/.
134 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
135 The U.S. military presence in Japan dates to the end of World War II. U.S. bases in Japan played major logistical
roles during the Korean and Vietnam Wars and formed an important element of America’s Cold War strategy in Asia.
For more information, see CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and
Issues for Congress, pp. 48-49.
136 Ibid., pp. 39-41.
137 Ibid., p. 41.
138 Irene Loewenson, “Marines Start Moving From Japan to New Base on Guam,” Marine Corps Times, December 29,
2023, https://www.marinecorpstimes.com/news/your-marine-corps/2023/12/29/new-in-2024-marines-start-moving-
from-japan-to-new-base-on-guam/. See also CRS In Focus IF10672, U.S. Military Presence on Okinawa and
Realignment to Guam.
139 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

32

U.S. Overseas Basing: Background and Issues for Congress

Mujuk, and Osan Air Base. These sites are used to base and support Army units (including the 2nd
Infantry Division/ROK-U.S. Combined Division) and Air Force fighter, reconnaissance, and
attack aircraft. Pursuant to a 2004 U.S.-ROK agreement, DOD installations are mainly
concentrated around two “hubs”: the first centers on the city of Pyeongtaek and includes Camp
Humphreys and Osan Air Base, while the second centers on Daegu and includes USAG-Daegu,
Fleet Activities Chinhae, and MCI Camp Mujuk.140 Uniquely, the U.S. and ROK militaries share
operational control of their forces in the country through the ROK/U.S. Combined Forces
Command, which acts as a unified, binational “warfighting headquarters.”141 U.S. basing posture
in South Korean is primarily organized around deterring and resisting potential DPRK
aggression.
According to DMDC, approximately 24,234 active-duty servicemembers were permanently
assigned to South Korea as of March 2024.142
The Marshall Islands, Micronesia, and Palau (Freely Associated States)
The United States maintains Army Garrison Kwajalein Atoll (which hosts the Ronald Reagan
Ballistic Missile Defense Test Site) in the Marshall Islands, and is currently constructing a radar
site in Palau.143 The U.S. military presence in the Freely Associated States is governed by the
Compacts of Free Association, which establish unique political relationships between the United
States and each FAS government.144 Per the terms of the Compacts, the United States has
responsibility for the defense of the FAS, as well as basing and access rights within FAS
territories.
According to DMDC, approximately 101 active-duty servicemembers were permanently assigned
to as the Freely Associated States of March 2024.145
The Philippines
The United currently has access to nine Philippine-operated defense sites under the terms of the
2014 U.S.-Philippines Enhanced Defense Cooperation Agreement (EDCA).146 Per the EDCA,
U.S. access to these sites is authorized “on a rotational basis, as mutually determined;” authorized
activities U.S. forces may conduct include “security cooperation exercises; joint and combined

140 For more information, see CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and
Issues for Congress, pp. 41-42 and 50. See also Terence Roehrig, “South Korea: An Alliance in Transition,” in Lord
and Erickson (ed.) Rebalancing U.S. Forces, pp.74-75.
141 “Mission of the ROK/U.S. Combined Forces Command,” U.S. Forces Korea, https://www.usfk.mil/About/CFC/.
142 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
143 CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and Issues for Congress, p. 39.
144 CRS In Focus IF12194, The Compacts of Free Association.
145 “Military and Civilian Personnel by Service/Agency by State/Country,” DMDC, March 2024, available for
download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
146 Between 1898 and 1946, the Philippines was a U.S. territory. The U.S. military maintained significant bases in the
Philippines, which played roles during World War II and the Vietnam War. The last persistent U.S. base in the country
closed in 1991. See CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and Issues for
Congress, pp. 47-50. “Philippines, U.S. Announce Four New EDCA Sites,” DOD, February 1, 2023,
https://www.defense.gov/News/Releases/Release/Article/3285566/philippines-usannounce-four-new-edca-sites/.
Congressional Research Service

33

U.S. Overseas Basing: Background and Issues for Congress

training activities; humanitarian assistance and disaster relief activities; and such other activities
as may be agreed upon.”147
According to DMDC, approximately 310 active-duty servicemembers were permanently assigned
to the Philippines as of March 2024.148
Singapore
The United States maintains a small permanent presence at its Navy Region Center Singapore,
which coordinates logistical support for visiting surface warships, and also conducts ongoing
rotational deployments of Littoral Combat Ships and P-8 Poseidon aircraft.149 Facilities to which
the U.S. military has access include Changi Naval Base and Sembawang shipyard, while Paya
Lebar Air Base may host U.S. servicemembers and aircraft on a rotational basis.150 Basing in
Singapore is governed by a number of executive agreements.151
According to DMDC, approximately 229 active-duty servicemembers were permanently assigned
to Singapore as of March 2024.152
Other Indo-Pacific Bases
In addition to the locations described above, DOD may have access to a number of other bases in
the region. For example, U.S. forces used a number of Thai military bases on a rotational basis
during the Global War on Terror (e.g., U-Tapao Royal Thai Navy Air Field), and in 2023 DOD
concluded an agreement with Papua New Guinea to allow U.S. forces access to six airports and
seaports in the country.153 U.S. Navy vessels also routinely conduct visits at a wide array of Indo-
Pacific regional ports.154

147 “Agreement between the Government of the United States of America and the Government of the Republic of the
Philippines on Enhanced Defense Cooperation,” signed April 28, 2014, https://www.state.gov/wp-content/uploads/
2019/02/14-625-Philippines-Defense-Cooperation.pdf.
148 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
149 CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and Issues for Congress , p. 43;
and “U.S. Security Cooperation with Singapore,” U.S. Department of State, April 12, 2023, https://www.state.gov/u-s-
security-cooperation-with-singapore/.
150 CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and Issues for Congress, pp. 16
and 43.
151 These include the 2019 U.S.-Singapore 2019 Amended MOU, the 2015 U.S.-Singapore EDCA, and the 2005 U.S-
Singapore Strategic Framework Agreement. “Fact Sheet: 2019 Protocol of Amendment to the 1990 Memorandum of
Understanding,” Singapore Ministry of Defense, September 24, 2019,
https://www.mindef.gov.sg/web/portal/mindef/news-and-events/latest-releases/article-
detail/2019/September/24sep19_fs; “Strategic Framework Agreement,” U.S. Department of State, 2005,
https://www.state.gov/wp-content/uploads/2019/02/05-712-Singapore-Defense-Cooperation.EnglishOCR.pdf; and
“Carter, Singapore Defense Minister Sign Enhanced Defense Cooperation Agreement,” DOD News, December 7,
2015, https://www.defense.gov/News/News-Stories/Article/Article/633243/carter-singapore-defense-minister-sign-
enhanced-defense-cooperation-agreement/.
152 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
153 Jim Garamone, “U.S., Thai Defense Leaders Look to Future in Indo-Pacific,” Department of Defense, May 13,
2022, https://www.defense.gov/News/News-Stories/Article/Article/3030852/us-thai-defense-leaders-look-to-future-in-
indo-pacific/. “U.S.-Papua New Guinea Agreement on Defense Cooperation,” Annex A, signed May 22, 2023,
https://www.state.gov/wp-content/uploads/2023/10/63374-Papua-New-Guinea-Defense-08.16.2023.pdf.
154 See “CNO: Port visits expanding across Asia-Pacific,” Navy Times, September 24, 2014,
https://www.navytimes.com/news/your-navy/2014/09/24/cno-port-visits-expanding-across-asia-pacific/.
Congressional Research Service

34

U.S. Overseas Basing: Background and Issues for Congress

Europe
U.S. overseas basing in Europe is established and governed by bilateral executive agreements
between the United States and regional governments, as well as the multilateral NATO SOFA
(except for Cyprus and Kosovo, all of the countries included in this section are members of
NATO).155 Most of the U.S. servicemembers permanently assigned to Europe are stationed at
persistent bases in Germany, Italy, and the United Kingdom. Over the past ten years (and
particularly following Russia’s 2022 invasion of Ukraine), the United States has established a
military presence in many Eastern European countries. In addition, DOD frequently conducts
rotational deployments in Europe involving tens of thousands of servicemembers. To reflect these
deployments, throughout this section CRS has supplemented DMDC-provided figures—which
only include permanently-assigned servicemembers—with reporting or estimates from other
sources, as appropriate.
Belgium
DOD maintains several administrative sites in Belgium, which are overseen by U.S. Army
Garrison Benelux.156 U.S. basing in Belgium mainly supports NATO activities, including support
for coordination with the nearby NATO headquarters in Belgium (the Supreme Headquarters
Allied Powers Europe, or SHAPE, is located in Casteau near Mons, Belgium).157
According to DMDC, approximately 1,106 active-duty servicemembers were permanently
assigned to Belgium as of March 2024.158
Bulgaria
The United States currently has access to four military facilities in Bulgaria under the terms of a
2008 cooperative security agreement.159 A bilateral agreement between Bulgaria and the U.S. also
permits up to 2,500 U.S. servicemembers to enter the country for military training.160 In March
2022, the U.S. Army deployed a Stryker armored-vehicle infantry company to support a NATO
battle group in the country, and U.S. Navy warships have made recurring port visits to Varna.161
DOD’s FY2023 Base Structure Report identifies the Novo Selo Training Area, and Graf Ignatievo
Air Base as DOD facilities, and Congress has appropriated funds for MILCON projects at these
bases.162

155 The NATO SOFA is available for download at https://www.nato.int/cps/en/natohq/official_texts_17265.htm.
156 U.S. Army, “U.S. Army Garrison Benelux Communities,” https://home.army.mil/benelux/about/communities.
157 NATO, “About Us,” https://shape.nato.int/about.
158 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
159 These facilities are: the Novo Selo Training Area, Bezmer Air Base, Graf Ignatievo Air Base, and a storage facility
in Aytos. “U.S. Bulgaria Partnership”, U.S. Embassy, Sofia, Bulgaria, April 9, 2008,
https://web.archive.org/web/20100325095350/http://bulgaria.usembassy.gov/shared_facilities_faq.html.
160 U.S. Department of State, Defense Cooperation Agreement between the United States and Bulgaria, April 26, 2006,
p. 5, https://www.state.gov/wp-content/uploads/2019/02/06-612-Bulgaria-Defense-Cooperation.done_.pdf.
161 “U.S. to Deploy Armored Unit to Bulgaria to Boost NATO's Eastern Flank”, Radio Free Europe/Radio Liberty,
March 19, 2022, https://www.rferl.org/a/us-stryker-deployment-bulgaria/31761140.html. U.S. Navy, “USS Arleigh
Burke Departs Varna, Bulgaria,” November 30, 2021, https://www.navy.mil/Press-Office/News-
Stories/Article/2856406/uss-arleigh-burke-departs-varna-bulgaria/.
162 Office of the Assistant Secretary of Defense for Energy, Installations, and Environment, FY2023 Base Structure
(continued...)
Congressional Research Service

35

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately 19 active-duty servicemembers were permanently assigned
to Bulgaria as of March 2024.163
Cyprus
The U.S. Air Force regularly deploys servicemembers and assets to RAF Akrotiri, a British
overseas base in Cyprus.164 Although little information concerning the U.S. presence in Cyprus is
publicly available, DOD’s FY2023 Base Structure Report lists RAF Akrotiri as a U.S. site, and in
2020 the Air Force initiated a $27 million MILCON project at RAF Akrotiri. 165
In November 2023, five U.S. servicemembers died in a helicopter crash off the coast of Cyprus;
they were reportedly special operations troops conducting a refueling training mission.166
According to DMDC, approximately 11 active-duty servicemembers were permanently assigned
to Cyprus as of March 2024.167
Estonia
DOD regularly conducts exercises in and rotational deployments to Estonia.168 In May 2023, for
instance, the U.S. Air Force sent F-22 Raptors to Ämari Air Base in Estonia, with the intent to “to
deter aggression in the Baltic Sea region,” and the U.S. Marine Corps conducted training
exercises in Estonia.169
Between FY2015 and FY2018, DOD received about $45 million in MILCON appropriations for
infrastructure improvements at Ämari Air Base.170

Report, https://www.acq.osd.mil/eie/BSI/BEI_Library.html. Also see Office of the Under Secretary of Defense
(Comptroller/Chief Financial Officer), Military Construction, Budget Estimates for Fiscal Years 2015-202, (C-1),
https://comptroller.defense.gov/Budget-Materials/Budget2024//
163 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
164 The Air Force lists an element of the 9th Reconnaissance Wing as being located at RAF Akrotiri, for instance, and
numerous DOD press releases have identified other Air Force personnel and units as being present at the base. See U.S.
Air Force, “9th Reconnaissance Wing,” https://www.16af.af.mil/About-Us/Unit-Fact-Sheets/Article/1962918/9th-
reconnaissance-wing/; and Tech Sgt. Chuck Marsh, “C-17 Globemaster Prepares for Takeoff,” DOD, at
https://www.defense.gov/Multimedia/Photos/igphoto/2001080448/.
165 DOD, FY2023 Base Structure Report, https://www.acq.osd.mil/eie/BSI/BEI_Library.html; Office of the Under
Secretary of Defense (Comptroller/Chief Financial Officer), Military Construction, Fiscal Year 2022 Budget Estimates,
(C-1), https://comptroller.defense.gov/Budget-Materials/Budget2020/; and Joint Explanatory Statement accompanying
P.L. 116-94, Division F, https://www.govinfo.gov/content/pkg/CREC-2019-12-17/pdf/CREC-2019-12-17-house-
bk3.pdf#page=330.
166 Dan Lamothe and Paulina Villegas, “Army identifies Special Operations soldiers Killed in ‘Mishap’ Over
Mediterranean,” The Washington Post, November 13, 2023, https://www.washingtonpost.com/national-
security/2023/11/12/military-helicopter-crash-mediterranean-5-killed/.
167 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
168 For example, DOD, “U.S. Army unit continues forging bonds with Estonian Allies,” December 21, 2023,
https://www.dvidshub.net/news/460537/us-army-unit-continues-forging-bonds-with-estonian-allies.
169 David Roza, “F-22 Raptors Deploy to Estonia to Bolster Baltic Air Defense,” Air and Space Force Magazine, May
15, 2023, https://www.airandspaceforces.com/air-force-f-22-raptor-nato-estonia/. Also see Office of the Under
Secretary of Defense (Comptroller), European Reassurance Initiative, Department of Defense Budget, May 17, 2018,
p. 15, https://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2018/fy2018_ERI_J-Book.pdf.
170 CRS analysis of DOD Under Secretary of Defense (Comptroller) Military Construction, Family Housing and Base
Realignment and Closure Program (C-1) documents, FY2015-FY2023, https://comptroller.defense.gov/Budget-
Materials/.
Congressional Research Service

36

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately 20 active-duty servicemembers were permanently assigned
to Estonia as of March 2024.171 In September 2023, media report about 600 U.S. servicemembers
in Estonia.172
Finland
The United States does not currently maintain a military presence in Finland, but in December
2023, the United States and Finland signed a Defense Cooperation Agreement that grants DOD
access to 15 Finnish military sites.173
According to DMDC, approximately 32 active-duty servicemembers were permanently assigned
to Finland as of March 2024.174
Germany
Since the end of World War II, Germany has hosted a large, enduring U.S. military presence,
including several large Army and Air Force bases.
The Army’s bases in Germany are grouped into five garrisons: U.S. Army Garrison Ansbach; U.S.
Army Garrison Bavaria (which includes the Grafenwoehr Training Area and the Hohenfels
Training Area, DOD’s largest permanent training areas in the region); U.S. Army Garrison
Rheinland-Pfalz; U.S. Army Garrison Stuttgart; and U.S. Army Garrison Wiesbaden.175 (Each
Army garrison may encompass multiple constituent sites—sometimes distributed across a wide
area—that are not listed individually in this report). Army assets assigned to locations in
Germany include a combat aviation brigade and a field artillery brigade.176
The U.S. Air Force in Germany includes a wing headquarters and a squadron of fighter aircraft
(F-16C/D Fighting Falcons) at Spangdahlem Air Base, as well as an air mobility wing
headquarters and reportedly a squadron of transport aircraft (C-130J-30 Hercules) at Ramstein Air
Base.177 Germany also hosts Landstuhl Regional Medical Center, DOD’s largest overseas medical
facility.178

171 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
172 Tetiana Fedosiuk, “The Signal of Deterrence and Reassurance,” The International Centre for Defence and Security,
September 8, 2023, https://icds.ee/en/the-signal-of-deterrence-and-reassurance/.
173 Finland also joined NATO in April 2023, departing from a long tradition of formal neutrality. U.S. Department of
State, “Secretary Antony J. Blinken at the Defense Cooperation Agreement Signing Ceremony,” December 18, 2023,
https://www.state.gov/secretary-antony-j-blinken-at-the-defense-cooperation-agreement-signing-ceremony/.
174 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
175 U.S. Army Europe and Africa, “Garrisons and Area Support Groups,”
https://www.europeafrica.army.mil/Garrisons/. U.S. Army Garrison Bavaria, “USAG Bavaria Fact Sheet,”
https://home.army.mil/bavaria/application/files/6316/1219/0614/USAG_Bv_Fact_Sheet_v1Feb21.pdf.
176 International Institute for Strategic Studies, “The Military Balance”, Figures and Maps, p. 48,
https://www.iiss.org/en/publications/the-military-balance/.
177 “480th FS demonstrates interoperability with German Tornados,” U.S. Air Force, May 18, 2023,
https://www.spangdahlem.af.mil/News/Article-Display/Article/3399435/480th-fs-demonstrates-interoperability-with-
german-tornados/. See also International Institute for Strategic Studies, “The Military Balance”, Figures and Maps, p.
48, https://www.iiss.org/en/publications/the-military-balance/ and U.S. Air Force, “Air Mobility Command Fact
Sheet,” July 2022, https://www.521amow.af.mil/About-Us/Fact-Sheets/Factsheet-Article-View/Article/3098986/air-
mobility-command/.
178 “USAG Rheinland-Pfalz Kaiserslautern Military Community: Medical Services”, Military One Source, at
(continued...)
Congressional Research Service

37

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately 35,068 active-duty servicemembers were permanently
assigned to Germany as of March 2024.179
Greece
The United States maintains Naval Support Activity (NSA) Souda Bay on the Greek island of
Crete, and frequently conducts exercises in and rotational deployments to the country.180
NSA Souda Bay includes one of the Mediterranean’s few deep-water ports, an all-weather
airfield, and refueling and resupply facilities.181 U.S. warships also conduct port visits to Piraeus
(near Athens), and the ports of Thessaloniki and Alexandroupolis support DOD logistical
operations in southeastern Europe, including activities related to security assistance for
Ukraine.182
The U.S. Air Force has conducted air mobility operations training exercises at Larissa Air Base.183
DOD has also reportedly used Larissa to support MQ-9 Reaper drones for Intelligence,
Surveillance and Reconnaissance (ISR) missions.184 Stefanovikeio Air Base also serves as a
rotational site for a U.S. Army aviation task force.185
According to DMDC, approximately 402 active-duty servicemembers were permanently assigned
to Greece as of March 2024.186

https://installations.militaryonesource.mil/military-installation/usag-rheinland-pfalz/health/health-care. Alexander
Riedel, “US Military Hospital to Replace 70-Year-Old Landstuhl is On Track for 2027, Officials Say,” Stars and
Stripes, April 20, 2023, https://www.stripes.com/theaters/europe/2023-04-20/landstuhl-hospital-70-year-legacy-
construction-progress-9852236.html. The Defense Health Agency is currently executing a military construction project
estimated to cost nearly $1 billion to build the Rhine Ordnance Barracks Medical Center, which will replace Landstuhl
and is scheduled to be completed in 2027.
179 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
180 The U.S.-Greece Mutual Defense Cooperation Agreement, updated in October 2021, provides the framework for
U.S. basing and military access. U.S. Department of State, “The United States and Greece,”, February 20, 2023,
https://www.state.gov/the-united-states-and-greece-united-by-democratic-values-advancing-shared-goals-for-peace-
and-prosperity.
181 U.S. Department of State, “U.S. Security Cooperation with Greece,” October 2022, https://www.state.gov/u-s-
security-cooperation-with-greece/. Also see Commander Navy Installations Command, Welcome to Naval Support
Activity Souda Bay, https://cnreurafcent.cnic.navy.mil/Installations/NSA-Souda-Bay/.
182 U.S. Army, “Port of Alexandroupolis Makes Sustainment History with Heavy Brigade Movement,” March 17,
2024, https://www.army.mil/article/274572/port_of_alexandroupolis_makes_sustainment_history. See also DOD,
“Strategic Port Access Aids Support to Ukraine, Austin Tells Greek Defense Minister,” July 18, 2022,
https://www.defense.gov/News/News-Stories/Article/Article/3097081/strategic-port-access-aids-support-to-ukraine-
austin-tells-greek-defense-minist/.
183 U.S. Air Force, “521st AMOW AMTs maneuver forces during DE23,” June 1, 2023,
https://www.safia.hq.af.mil/IA-News/Article/3417550/521st-amow-amts-maneuver-forces-during-de23/.
184 Elisabeth Gosselin-Malo, “Upgraded Greek Air Base Serves Growing Interest for US drones,” Defense News,
December 13, 2022, https://www.defensenews.com/global/europe/2022/12/13/upgraded-greek-air-base-serves-
growing-interest-for-us-drones/.
185 Defense Visual Information Distribution Service, “Mutual Defense Cooperation Agreement Enhances U.S. Army
and Greek Partnership,” October 20, 2021, https://www.dvidshub.net/news/407866/mutual-defense-cooperation-
agreement-enhances-us-army-and-greek-partnership.
186 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

38

U.S. Overseas Basing: Background and Issues for Congress

Greenland (Denmark)
The United States maintains Pittufik Space Base (formerly known as Thule Air Base) in
Greenland, an autonomous territory of Denmark. Pittufik is DOD’s northernmost overseas base,
and supports space domain awareness and surveillance, missile warning and defense, and related
functions.187
According to DMDC, approximately 135 active-duty servicemembers were permanently assigned
to Greenland as of March 2024.188
Hungary
DOD conducts rotational deployments to and exercises in Hungary. In July 2021, U.S. European
Command and Hungarian Defense Force leaders signed agreements designating Kecskemét Air
Base and Pápa Air Bases as “agreed facilities and areas.”189 In July 2023, the U.S. Air Force
deployed two rescue squadrons to Papa Air Base for an exercise, and in May 2023, soldiers from
the 101st Airborne Division were deployed at Camp Croft near Veszprém.190
In FY2023, DOD initiated a $71 million project at Papa Air Base to install a Deployable Air Base
System.191
According to DMDC, approximately 84 active-duty servicemembers were permanently assigned
to Hungary as of March 2024.192
Iceland
Iceland hosts U.S. maritime patrol and reconnaissance aircraft at Keflavik Air Base.193 Since
FY2017, Congress has appropriated over $185 million for MILCON projects at Keflavik.194

187 U.S. Space Force, “Pittufik Space Base,” https://www.petersonschriever.spaceforce.mil/Pituffik-SB-Greenland.
188 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
189 U.S. Embassy in Hungary, “U.S., Hungary sign Implementing Agreements for Use of Air Bases,” July 21, 2021,
https://hu.usembassy.gov/u-s-hungary-sign-implementing-agreements-for-use-of-air-bases/.
190 “Jolly Vihar 23 enhances US, Hungarian air forces interoperability,” U.S. Air Force, July 3, 2023,
https://www.af.mil/News/Article-Display/Article/3447366/jolly-vihar-23-enhances-us-hungarian-air-forces-
interoperability/; and “Ambassador Pressman Visits U.S. Servicemembers Near Veszprém,” U.S. Embassy in Hungary,
May 4, 2023, at https://hu.usembassy.gov/news-ambassador-pressman-visits-u-s-servicemembers-near-veszprem/.
191 Deployable Air Base Systems typically include the materials needed to stand up air operations, including temporary
billeting and mess facilities, vehicles, airfield repair resources, and power and electrical equipment. See Department of
Defense Budget Fiscal Year (FY) 2023, Office of the Under Secretary of Defense (Comptroller), April 2022, p. 30,
https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2023/FY2023_EDI_JBook.pdf.
192 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
193 During the Cold War, Iceland hosted a permanent U.S. presence at Keflavik; this presence ended in 2006, but U.S.
deployments to Keflavik began again in 2016. For more information, see Atlantic Council, “Cast Off by the United
States A Decade Ago, Keflavik is Again a Key Lookout,” May 7, 2018, https://www.atlanticcouncil.org/blogs/new-
atlanticist/cast-off-by-the-united-states-a-decade-ago-keflavik-is-again-a-key-lookout.
194 CRS analysis of DOD Under Secretary of Defense (Comptroller) Military Construction, Family Housing and Base
Realignment and Closure Program (C-1) documents, FY2017-FY2023, https://comptroller.defense.gov/Budget-
Materials/.
Congressional Research Service

39

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately three active-duty servicemembers were permanently
assigned to Iceland as of March 2024.195 Air Force and Navy units have deployed to Keflavik for
exercises and temporary duties, including a detachment of Navy anti-submarine aircraft.196
Italy
Since the end of World War II, Italy has hosted a large, persistent U.S. military presence,
including several large Army, Navy, and Air Force bases.
U.S. Army Garrison Italy, with a headquarters at Camp Ederle in Vicenza, is home to an airborne
infantry brigade combat team that serves as a rapid response force for European, African, and
Middle Eastern locations.197
Aviano Air Base hosts two F-16 fighter squadrons and a helicopter rescue squadron.198
Naval Support Activity Naples hosts the headquarters for U.S. Naval Forces Europe and Africa
and the U.S. 6th Fleet. The U.S. 6th Fleet Blue Ridge-class command and control ship, the USS
Mount Whitney (LCC 20), is homeported in near Naples at Gaeta.199 Naval Air Station Sigonella
in Sicily hosts a rotational presence of Navy P-8A Poseidon anti-submarine aircraft, as well as a
squadron of Marine Corps MV-22 Osprey tilt-rotor aircraft.200 The Air Force also reportedly
maintains unmanned ISR aircraft at Sigonella.201
According to DMDC, approximately 12,375 active-duty servicemembers were permanently
assigned to Italy as of March 2024.202
Kosovo
Since 1999, the United States has maintained military forces in Kosovo to support NATO’s
Kosovo Force (KFOR), a peacekeeping effort. The U.S. Army’s Area Support Group – Balkans

195 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
196 See, for example, Defense Visual Information Distribution Service, “Chief of Naval Operations visits Patrol
Squadron Nine in Keflavik, Iceland,” June 15, 2022, https://www.dvidshub.net/news/426594/chief-naval-operations-
visits-patrol-squadron-nine-keflavik-iceland. See also U.S. Air Force, “U.S. B-2 Spirit Bombers deploy to Keflavik Air
Base for Bomber Task Force 23-4,” August 14, 2023, https://www.usafe.af.mil/News/Article-
Display/Article/3491598/us-b-2-spirit-bombers-deploy-to-keflavik-air-base-for-bomber-task-force-23-4/.
197 “U.S. Army Garrison Italy,” Military One Source, https://installations.militaryonesource.mil/in-depth-
overview/usag-italy; and U.S. Army, “173rd Airborne Brigade—Our Mission,”
https://www.skysoldiers.army.mil/About-Us/Mission/.
198 U.S. Air Force, “Aviano Air Force Base Fact Sheet,” https://www.aviano.af.mil/About-Us/Fact-
Sheets/Display/Article/280335/31st-fighter-wing/.
199 U.S. Navy, “USS Mount Whitney Departs Homeport,” October 18, 2023, https://www.navy.mil/Press-Office/News-
Stories/Article/3561127/uss-mount-whitney-departs-homeport/.
200 U.S. Naval Forces Europe and Africa / U.S. Sixth Fleet, “Patrol Squadron 9 Begins Inaugural P-8A Poseidon
Deployment,” April 13, 2019, https://www.c6f.navy.mil/Press-Room/News/News-Display/Article/1845325/patrol-
squadron-9-begins-inaugural-p-8a-poseidon-deployment/; and Alison Bath, “Marine Tilt-Rotor Squadron Shifts from
Spain to Sicily,” Stars and Stripes, December 29, 2021, https://www.stripes.com/branches/marine_corps/2021-12-
29/marines-tiltrotor-squadron-assigned-to-nas-sigonella-4119389.html.
201 The Military Balance, International Institute for Strategic Studies, 2023, p. 48,
https://www.iiss.org/en/publications/the-military-balance/.
202 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

40

U.S. Overseas Basing: Background and Issues for Congress

maintains a headquarters for U.S. military activity in the Balkans at Camp Bondsteel in
Kosovo.203
According to DMDC, approximately 14 active-duty servicemembers were permanently assigned
to Kosovo as of March 2024.204 However, according to a December 2023 letter submitted by the
Biden Administration to congressional leaders regarding the War Powers Report “approximately
578 United States military personnel are [present in Kosovo] among KFOR’s approximately
4,487 personnel.”205
Latvia
DOD regularly conducts exercises in and rotational deployments to Latvia. A U.S. Marine
Expeditionary Unit made a port visit to Latvia in September 2023.206 Between 2015 and 2018,
DOD received $13 million in military construction appropriations funds for infrastructure
improvements at Lielvarde Air Base.207
According to DMDC, approximately 19 active-duty servicemembers were permanently assigned
to Latvia as of March 2024.208 However, media reports suggest the United States reportedly
deployed about 600 servicemembers deployed to Latvia in 2022, including some rotational forces
at Lielvarde Air Base.209
Lithuania
DOD regularly conducts exercises in and rotational deployments to Lithuania. In December 2022,
the U.S. Embassy in Lithuania announced the intent to maintain a “persistent rotational presence”
of a U.S. Army armored battalion and field artillery battery in Lithuania. The Lithuanian
government built Camp Herkus at the Pabrade Training Area to support an increased U.S. military
presence in the country, and has reportedly requested that the United States establish a permanent

203 In addition, the Kosovar government has reportedly requested a permanent U.S. military base in the country. U.S.
Army, “Area Support Group -- Balkans U.S. Army,” https://www.21tsc.army.mil/Units/Area-Support-Group-Balkans/;
and “Kosovo Asks U.S. for Permanent Base, Speedier NATO Membership,” Reuters, February 27, 2022,
https://www.reuters.com/world/europe/kosovo-asks-us-permanent-military-base-speedier-nato-membership-2022-02-
27/.
204 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
205 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” December 7, 2023, https://www.whitehouse.gov/briefing-room/presidential-
actions/2023/12/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-
regarding-the-war-powers-report/.
206 U.S. Navy, “U.S. Navy and Marines Arrive in Latvia for the Upcoming German Baltic Sea Exercise Northern Coast
2023,” September 8, 2023, https://www.navy.mil/Press-Office/News-Stories/Article/3520154/us-navy-and-marines-
arrive-in-latvia-for-the-upcoming-german-baltic-sea-exercis/.
207 CRS analysis of DOD Under Secretary of Defense (Comptroller) Military Construction, Family Housing and Base
Realignment and Closure Program (C-1) documents, FY2015-FY2023, https://comptroller.defense.gov/Budget-
Materials/.
208 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
209 Alex Horton, Karoun Demirjian and Michael Birnbaum, “U.S. Allies Most Vulnerable to Russia Press for More
Troops, Weapons,” Washington Post, August 13, 2022, https://www.washingtonpost.com/national-
security/2022/08/13/us-military-baltics-russia/.
Congressional Research Service

41

U.S. Overseas Basing: Background and Issues for Congress

base in the country.210 U.S. Army soldiers trained at Camp Herkus in April 2022;211 and U.S.
soldiers also conducted training exercises with Lithuanian military units at the Pabrade Training
Area in November 2023.212
According to DMDC, approximately 19 active-duty servicemembers were permanently assigned
to Lithuania as of March 2024.213 However, in March 2023, the Lithuanian government reported
that 966 U.S. servicemembers were present in the country.214
Norway
The U.S. Air Force maintains the 426th Air Base Squadron at the Jåttå Military Compound in
Stavanger, Norway, which serves as the U.S. National Support Element for the NATO Joint
Warfare Centre.215
In April 2021, the U.S. and Norway signed a security agreement that provides for the U.S.
military “to access specific Norwegian facilities and conduct activities for our mutual defense.”216
The “focal points for increased cooperation with Norway” include: Evenes Air Station, Ramsund
Naval Station, Rygge Air Station, and Sola Air Station.217
The Marine Corps has conducted training exercises in Norway, and maintains a stockpile of
prepositioned material in the country. 218
According to DMDC, approximately 1,438 active-duty servicemembers were permanently
assigned to Norway as of March 2024.219
Poland
In March 2023, the Army began to permanently assign soldiers to the Victory Corps, or V Corps,
forward headquarters at Camp Kosciuszko, in Poznan, Poland.220 U.S. Army Garrison Poland
supports three forward operating sites (FOS) in Poland: Camp Kosciuszko in Poznan, FOS

210 Jacqueline Feldscher, “Is This the Next US Military Base in Europe?,” Defense One, October 3, 2021, at
https://www.defenseone.com/policy/2021/10/next-us-military-base-europe/185808/; and Jordan Williams , “Lithuanian
president to ask for permanent US troop presence”, The Hill, February 9, 2022,
https://thehill.com/policy/defense/593512-lithuanian-president-to-ask-for-permanent-us-troop-presence/.
211 Defense Visual Information Distribution Center, “Force Protection Drill at Camp Herkus,” April 14, 2022,
https://www.dvidshub.net/image/7157629/force-protection-drill-camp-herkus.
212 U.S. Army, “Task Force Marne troops train alongside NATO allies during Strong Griffin exercise in Lithuania,”
November 17, 2023, https://www.army.mil/article/271786/.
213 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
214 Ibid., see also “Prime Minister thanks US troops in Lithuania,” Government of the Republic of Lithuania, March 31,
2023, https://lrv.lt/en/news/prime-minister-thanks-us-troops-in-lithuania.
215 U.S. Air Force, “426th Air Base Squadron,” https://www.501csw.usafe.af.mil/Units/423d-ABG/426th-ABS/.
216 U.S. Department of State, “U.S.-Norway Supplementary Defense Cooperation Agreement (SDCA),” April 16, 2021,
https://www.state.gov/u-s-norway-supplementary-defense-cooperation-agreement-sdca/.
217 Ibid.
218 “26th MEU(SOC) Concludes Training in Norway,” U.S. Marine Corps, August 25, 2023,
https://www.marines.mil/News/News-Display/Article/3506238/26th-meusoc-concludes-bi-lateral-training-in-norway/.
219 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
220 U.S. Army, “First Permanently Assigned US Soldiers arrive in Poland,” March 8, 2023,
https://www.army.mil/article/264637/first_permanently_assigned_us_soldiers_arrive_in_poland.
Congressional Research Service

42

U.S. Overseas Basing: Background and Issues for Congress

Powidz, and FOS Zagan.221 Other locations in Poland that periodically support U.S. rotational
forces include Skwierzyna, Świętoszów, Drawsko Pomorskie, Bolesławiec and Toruń.222 More
than 100 infrastructure projects to support the U.S. military in Poland are reportedly in the works,
ranging from dining facilities and barracks to training ranges.223 Most U.S. troops in Poland are
reportedly there on nine-month rotations.224
U.S. military capabilities in Poland reportedly include an armor brigade; Patriot surface-to-air
missile defense systems; F-22 Raptor combat aircraft; and unmanned ISR aircraft.225
The U.S. military is also installing an Aegis Ashore Ballistic Missile Defense (AABMD) system
at Naval Support Facility Redzikowo, a former military and civilian airfield 225 miles northwest
of Warsaw; NSF Redzikowo – which DOD has referred to as “the Navy’s newest base” – is
operated in conjunction with the Polish Force Protection Battalion.226
U.S. Air Force F-16 units have deployed to Lask Air Base near Lodz, Poland, and F-22s have
deployed to Powidz Air Base in Poland to support NATO Allied Air Command’s Air Shielding
mission along NATO’s eastern flank.227 The U.S. Air Force also reportedly operates air-refueling
aircraft from Powidz Air Base.228
According to DMDC, as of March 2024, 299 active-duty U.S. military servicemembers were
permanently assigned to Poland.229 However, in October 2022, the U.S. State Department
reported that the U.S. maintains a rotational force of about 10,000 servicemembers in Poland,
which includes an armored brigade combat team, funded through the European Deterrence
Initiative.230

221 U.S. Army, “Army Establishes Permanent Garrison in Poland,” March 21, 2023,
https://www.army.mil/article/265027/army_establishes_permanent_garrison_in_poland.
222 Government of Poland, “Increasing the US Military Presence in Poland,” https://www.gov.pl/web/national-
defence/increasing-the-us-military-presence-in-poland.
223 John Vandiver, “Army’s New Poland Garrison went from Warsaw’s Wish List to high US Priority,” Stars and
Stripes, March 28, 2023, https://www.stripes.com/theaters/europe/2023-03-28/army-poland-base-9627391.html.
224 Ibid.
225 The Military Balance, IISS, p. 49, https://www.iiss.org/en/publications/the-military-balance/.
226 U.S. Navy, “Navy Commissions Naval Support Facility Redzikowo,” September 3, 2020,
https://www.navy.mil/DesktopModules/ArticleCS/Print.aspx?PortalId=1&ModuleId=523&Article=2336225; and
DVIDS, “Naval Support Facility Redzikowo Conducts Change of Command,” December 15, 2022,
https://www.dvidshub.net/image/7559906/naval-support-facility-redzikowo-conducts-change-command.
227 U.S. Air Force “52nd Fighter Wing F-16s deploy to NATO’s Eastern Flank,”, October 3, 2023,
https://www.usafe.af.mil/News/Press-Releases/Display/Article/3545712/52nd-fighter-wing-f-16s-deploy-to-natos-
eastern-flank/; and “F-22s Conduct Joint Training with Romanian and Italian Air Forces,” U.S. Air Force, May 25,
2023, https://www.usafe.af.mil/News/Press-Releases/Display/Article/3406930/f-22s-conduct-joint-training-with-
romanian-and-italian-air-forces/.
228 Jennifer H. Svan, “US Air Force shifts refueling mission from Germany to Poland,” Stars and Stripes, April 24,
2023, https://www.stripes.com/branches/air_force/2023-04-24/tankers-poland-powidz-9902489.html.
229 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
230 Department of State, “U.S. Security Cooperation with Poland,” October 31, 2022, https://www.state.gov/u-s-
security-cooperation-with-poland/.
Congressional Research Service

43

U.S. Overseas Basing: Background and Issues for Congress

Portugal
The U.S. Air Force operates Lajes Field in the Azores Islands, a Portuguese territory located
about 1,000 miles west of continental Europe. Lajes Field is the home of the 65th Air Base Wing,
which supports trans-Atlantic military operations.231
According to DMDC, as of March 2024, 247 active-duty U.S. military servicemembers were
permanently assigned to Portugal.232
Romania
Romania hosts a rotational presence of U.S. forces at several military facilities. In April 2023, the
EUCOM commander testified that the rotational presence in Romania at that time included a U.S.
Division headquarters, a U.S. brigade combat team, and a U.S. helicopter battalion.233
U.S. bomber aircraft have conducted refueling exercises at Mihail Kogălniceanu Air Base,
Romania.234 F-22 units have conducted training at Camp Turzii, Romania, to support NATO
Allied Air Command’s Air Shielding mission along the eastern flank.235
The U.S. Navy operates an Aegis Ashore Missile Defense System (AAMDS) site in Romania at
Naval Support Facility (NSF) Deveselu.236
DOD reports Mihail Kogălniceanu Air Base, Turzii, and NSF Deveselu as DOD facilities on the
FY2023 Base Structure Report and the three facilities have received MILCON funding.237
According to DMDC, as of March 2024, 139 active-duty U.S. military servicemembers were
permanently assigned to Romania.238 However, according to the U.S. Department of State, in
February 2023 approximately 3,000 DOD personnel were present in Romania.239
Spain
Spain hosts U.S. Navy and Air Force bases.

231 U.S. Air Force, “65th Air Base Wing,” https://www.af.mil/News/Photos/igphoto/2000552780/mediaid/10485/.
232 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
233 U.S. Congress, House Committee on Armed Services, Statement of General Christopher Cavoli, United States
Army, U.S. European Command, 118th Cong., 1st sess., April 26, 2023, p. 33,
https://www.eucom.mil/document/42365/housearmedservicesonchallengesineurope-politicopropdf.
234 U.S. Air Force, “B-1B Lancers receive first-ever hot-pit in Romania,” June 13, 2023,
https://www.usafe.af.mil/News/Press-Releases/Display/Article/3425782/b-1b-lancers-receive-first-ever-hot-pit-in-
romania/.
235 U.S. Air Force, “F-22s conduct joint training with Romanian and Italian air forces,” May 25, 2023,
https://www.usafe.af.mil/News/Press-Releases/Display/Article/3406930/f-22s-conduct-joint-training-with-romanian-
and-italian-air-forces/.
236 U.S. Navy, “U.S. AEGIS Ashore Missile Defense System Romania Changes Command,” September 18, 2021,
https://www.navy.mil/Press-Office/News-Stories/Article/2781280/us-aegis-ashore-missile-defense-system-romania-
changes-command/.
237 DOD, FY2023 Base Structure Report, https://www.acq.osd.mil/eie/BSI/BEI_Library.html.
238 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
239 U.S. Department of State, U.S. Security Cooperation with Romania, Fact Sheet, February 14, 2023,
https://www.state.gov/u-s-security-cooperation-with-romania.
Congressional Research Service

44

U.S. Overseas Basing: Background and Issues for Congress

Naval Station Rota, located near the Strait of Gibraltar, provides cargo, fuel, and logistics support
to Navy ships and military units transiting the region.240 The U.S. Navy homeports four Arleigh
Burke-class destroyers in Rota.241 The destroyers are equipped with Aegis Baseline 9 Ballistic
Missile Defense systems and are a component of EUCOM’s regional missile defense strategies.242
The U.S. and the government of Spain announced in May 2023 an agreement to expand the size
of the Navy fleet authorized to homeport in Rota from four warships to six.243
Moron Air Base is about 75 miles northeast of Naval Station Rota. Moron hosts the 496th Air
Base Squadron and provides logistical support for moving military equipment and personnel into
EUCOM and other regional combatant commands; it has large runways and a refueling
systems.244
According to DMDC, as of March 2024, 3,292 active-duty U.S. military servicemembers were
permanently assigned to Spain.245
Türkiye
Türkiye hosts U.S. Air Force and Army bases.
The Air Force operates aviation facilities at Incirlik Air Base and a rotational presence of aerial
refueling capabilities.246 Several open-source media outlets have speculated about whether U.S.
tactical nuclear weapons are based at Incirlik Air Base.247 While Incirlik is located in the EUCOM
AOR, the facilities and personnel there frequently support operations in CENTCOM.248
Other key U.S./NATO sites in Türkiye include an early warning missile defense radar in Kürecik
in eastern Türkiye.249 Izmir Air Station hosts a headquarters for NATO Allied Land Command.250

240 The installation has three active piers, a 670-acre airfield, and the largest weapons and fuels facilities in Europe. See
Commander, Navy Region Europe, Africa, Central, Naval Station Rota, Installation Information,
https://cnreurafcent.cnic.navy.mil/Installations/NAVSTA-Rota/.
241 U.S. Navy, “Destroyers (DDG 51) Fact Sheet,” October 2022, https://www.navy.mil/Resources/Fact-Files/Display-
FactFiles/Article/2169871/destroyers-ddg-51/. Also see U.S. Navy, “USS Bulkeley (DDG 84), latest FDNF-E ship,
arrives in new homeport Rota, Spain,” press release, August 17, 2022, https://www.navy.mil/Press-Office/News-
Stories/Article/3130658/uss-bulkeley-ddg-84-latest-fdnf-e-ship-arrives-in-new-homeport-rota-spain/.
242 U.S. Navy, Destroyers (DDG 51), Fact Sheet, October 2022, https://www.navy.mil/Resources/Fact-Files/Display-
FactFiles/Article/2169871/destroyers-ddg-51/.
243 Heather Mongilio, “U.S., Spain Agree to Host Two More Warships in Rota”, U.S. Naval Institute, May 9, 2023,
https://news.usni.org/2023/05/09/u-s-spain-agree-to-host-two-more-warships-in-rota.
244 Ramstein Air Base, “Welcome to Morón AB”, https://www.ramstein.af.mil/About/Units/496-ABS-Moron/.
245 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
246 Defense Visual Information Distribution Center, “384th EARS deploys to Incirlik AB, continues air refueling
mission,” press release, October 21, 2021, https://www.dvidshub.net/image/6928282/384th-ears-deploys-incirlik-ab-
continues-air-refueling-mission.
247 Ibid. p. 53. See also, Zachary Cohen, “Trump appears to confirm open secret about US nuclear weapons in
Türkiye”, CNN, October 16, 2019, https://www.cnn.com/2019/10/16/politics/trump-us-nuclear-weapons-
Türkiye/index.html.
248 Ibid.
249 CRS Report R41368, Turkey (Türkiye): Background and U.S. Relations, by Jim Zanotti and Clayton Thomas, p. 53.
250 NATO, “Allied Land Command,” https://lc.nato.int/. See also Defense Visual Information Distribution Service,
“NATO Allied Land Command Welcomes New Commander,” August 4, 2022,
https://www.dvidshub.net/image/7352516/nato-allied-land-command-welcomes-new-commander.
Congressional Research Service

45

U.S. Overseas Basing: Background and Issues for Congress

Diplomatic tensions between the U.S. and Türkiye have reportedly prompted the Turkish
government in some situations to consider imposing limits on U.S. military access to Incirlik.251
According to DMDC, as of March 2024, 1,690 active-duty U.S. military servicemembers were
permanently assigned to Türkiye.252
United Kingdom
Royal Air Force Lakenheath is the headquarters for the U.S. Air Force’s 48th Fighter Wing, which
is the U.S. Air Force’s only fourth- and fifth-generation fighter wing in Europe; it includes F-35A
Lightening II Joint Strike Fighters and F-15E Strike Eagles.253 In addition to combat aircraft, U.S.
military capabilities in the U.K. reportedly include tanker refueling aircraft (KC-135R/T
Stratotankers), ISR aircraft, and V-22 Osprey tilt-rotor aircraft.254 U.S. Strategic Command also
reportedly maintains AN/FPS-132 Upgraded Early Warning Radar in the U.K..255
RAF Mildenhall hosts the 100th Air Refueling Wing, which operates KC-135 Stratotanker
aircraft.256 RAF Alconbury is a U.S. facility that hosts U.S. rotational forces.257 RAF Molesworth
is home to the EUCOM Joint Intelligence Operations Center Europe Analytic Center.258
Bases in the U.K. also host rotational deployments of U.S. Air Force bomber aircraft from U.S.-
based units.259
According to DMDC, as of March 2024, 10,058 active-duty U.S. military servicemembers were
permanently assigned to the United Kingdom.260

251 U.S. relations with Turkey have deteriorated since 2016 after a cadre of Turkish military officers attempted an
unsuccessful coup and some U.S. officials were accused of supporting the coup. See Kyle Rempfer, “Turkish lawyers
want to raid İncirlik Air Base and arrest US Air Force officers,” Air Force Times August 9, 2018,
https://www.airforcetimes.com/news/your-air-force/2018/08/09/turkish-lawyers-want-to-raid-incirlik-air-base-and-
arrest-us-air-force-officers/. Also see John Vandiver, “Turkey warns sanctions could jeopardize US access to Incirlik
Air Base,” Stars and Stripes, December 11, 2019, https://www.stripes.com/theaters/europe/turkey-warns-sanctions-
could-jeopardize-us-access-to-incirlik-air-base-1.610663.
252 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
253 U.S. Air Force, “Royal Air Force Lakenheath,” https://www.lakenheath.af.mil/About-Us/.
254 International Institute for Strategic Studies, The Military Balance, Indexes of Tables, Figures and Maps, p. 49,
https://www.iiss.org/en/publications/the-military-balance/.
255 International Institute for Strategic Studies, The Military Balance, Indexes of Tables, Figures and Maps, p. 49,
https://www.iiss.org/en/publications/the-military-balance/.
256 U.S. Air Force, “100th Air Refueling Wing,” January 2023, https://www.mildenhall.af.mil/About-Us/Fact-
Sheets/Display/Article/270378/100th-air-refueling-wing/.
257 U.S. Air Force, “RAF Alconbury to remain as a Base for the US Visiting Forces,” March 22, 2021,
https://www.501csw.usafe.af.mil/News/Article-Display/Article/2545509/raf-alconbury-to-remain-as-a-base-for-the-us-
visiting-forces/.
258 510st Combat Support Wing, “JIOCEUR Analytic Center changes command,” July 11, 2022,
https://www.501csw.usafe.af.mil/News/Article-Display/Article/3088754/jioceur-analytic-center-changes-command/.
259 U.S. European Command, “Bomber Task Force Europe: Supersonic bombers complete successful rotation,” June
29, 2023, https://www.eucom.mil/article/42426/bomber-task-force-europe-supersonic-bombers-complete-successful-
rotation.
260 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

46

U.S. Overseas Basing: Background and Issues for Congress

Middle East
U.S. overseas basing in the Middle East is established and governed by bilateral executive
agreements between the United States and regional governments—except in the case of Syria,
where U.S. forces are present despite the opposition of Syria’s government. Unlike in the Indo-
Pacific or Europe, many U.S. servicemembers present in the Middle East appear to be on
temporary or rotational assignments, and are thus not accounted for by DMDC’s figures. To
reflect this, throughout this section CRS has supplemented DMDC-provided figures—which only
include permanently-assigned servicemembers—with reporting or estimates from other sources,
as appropriate. Some DOD documents and statements relating to this region refer to U.S. forces
being deployed to and operating from “Southwest Asia,” which may designate any number of
locales (the usage of this term may reflect both operational security concerns and host-nation
political sensitivities).
Bahrain
Bahrain hosts the U.S. Navy’s Fifth Fleet and U.S. Naval Forces Central Command (NAVCENT)
headquarters at an installation known as Naval Support Activity (NSA) Bahrain.261 The U.S.
Navy’s base in Bahrain is one of the most enduring U.S. military sites in the region; the Navy’s
use of the facility dates back to 1948, when the base was operated by Britain’s Royal Navy.262
The deep-water port in Bahrain is one of the few facilities in the Persian Gulf that accommodates
U.S. aircraft carriers and amphibious assault ships.263 Navy ships homeported in Bahrain include
four mine countermeasures ships (MCMs), one Expeditionary Support Base (ESB) ship, and two
logistical support ships operated by the Military Sealift Command (MSC).264 DOD capabilities in
Bahrain reportedly include P-8 Poseidon (an American maritime patrol and reconnaissance
aircraft), EP-3E Aries II reconnaissance aircraft, and Patriot missile defense systems.265
The U.S. Coast Guard, which is overseen by the U.S. Department of Homeland Security, also
maintains a squadron of ships in Bahrain, which consists of six fast response cutters, a cutter
relief crew, and a 150-member mission support detachment.266
According to DMDC, as of March 2024, 3,479 active-duty U.S. military servicemembers were
permanently assigned to Bahrain.267 However, DOD has also reported a total presence of 9,000
service members and DOD civilians.268 It is likely that the number of DOD personnel fluctuates
with the arrival and departure of U.S. ships.

261 CRS Report 95-1013, Bahrain: Issues for U.S. Policy, by Jeremy M. Sharp.
262 U.S. Navy, “Naval Support Activity Bahrain,” https://cnreurafcent.cnic.navy.mil/Installations/NSA-
Bahrain/About/History/.
263 Dion Nissenbaum, “Israel’s President Visits Bahrain to Address Stalled Relations,” The Wall Street Journal,
December 4, 2022, https://www.wsj.com/articles/israels-president-heads-to-bahrain-to-address-stalled-arab-relations-
11670133603.
264 U.S. Navy, “Mine Countermeasures Ships (MCM),” https://www.navy.mil/Resources/Fact-Files/Display-
FactFiles/Article/2171622/mine-countermeasures-ships-mcm/.
265 IISS, The Military Balance, p. 47, https://www.iiss.org/en/publications/the-military-balance/.
266 U.S. Coast Guard, “Patrol Forces Southwest Asia,” https://www.atlanticarea.uscg.mil/Our-Organization/Area-
Units/PATFORSWA/.
267 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
268 “Naval Support Activity Bahrain, Installation Overview”, Military One Source,
https://installations.militaryonesource.mil/in-depth-overview/naval-support-activity-bahrain.
Congressional Research Service

47

U.S. Overseas Basing: Background and Issues for Congress

Egypt
The U.S. military maintains a presence in Egypt as part of its support to the Multinational Force
and Observers (MFO), an international peacekeeping force intended to “supervise the
implementation of the security provisions of the Egyptian-Israeli Treaty of Peace and employ best
efforts to prevent any violation of its terms.”269
DOD also periodically participates in joint training and exercises with the Egyptian military,
including at Cairo West Air Base.270
According to DMDC, as of March 2024, 176 active-duty U.S. military servicemembers were
permanently assigned to Egypt.271 However, according to a December 2023 letter submitted by
the Biden Administration to congressional leaders regarding the War Powers Report, 416 military
DOD personnel were present in Egypt as part of the U.S. commitment to the MFO.”272
Iraq
U.S. servicemembers are based at a number of locations inside Iraq, including Al Asad Air Base
and Erbil Air Base. 273 According to the White House, the purpose of the U.S. presence in Iraq is
to “advise, assist, and enable select elements of the Iraqi security forces…[and] provide limited
support to the North Atlantic Treaty Organization mission in Iraq.”274 On a bilateral basis, the
U.S. military presence in Iraq is governed by an exchange of diplomatic notes that reference the
security provisions of the 2008 bilateral Strategic Framework Agreement.275 To date, this
arrangement has not required the approval of a separate security agreement by Iraq’s Council of
Representatives. According to former Special Presidential Envoy for the Global Coalition to
Counter ISIL Brett McGurk, the 2014 U.S.-Iraq diplomatic notes, which are not public, contain a
one-year cancelation clause.276

269 MFO, “Multinational Force & Observers,” https://mfo.org/. See also CRS Report RL33003, Egypt: Background and
U.S. Relations.
270 DOD, “179th Expeditionary Fighter Squadron deploys to Egypt in support of Agile Phoenix 22,” June 27, 2022,
https://www.dvidshub.net/image/7310379/179th-expeditionary-fighter-squadron-deploys-egypt-support-agile-phoenix-
22-image-1-11.
271 DMDC, “Military and Civilian Personnel by Service/Agency by State/Country,” March 2024, available for
download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
272 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” December 7, 2023, https://www.whitehouse.gov/briefing-room/presidential-
actions/2023/12/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-
regarding-the-war-powers-report/.
273 DOD, “Into Iraq: Task Force Redleg Assumes Authority of Al Asad Air Base,” August 12, 2023,
https://www.dvidshub.net/news/453071/into-iraq-task-force-redleg-assumes-authority-al-asad-air-base.DOD, and
“CENTCOM Senior Enlisted Leader Visits Erbil Air Base,” DOD, July 10, 2023, at
https://www.dvidshub.net/image/7918505/centcom-senior-enlisted-leader-visits-erbil-air-base.
274 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” December 7, 2023, https://www.whitehouse.gov/briefing-room/presidential-
actions/2023/12/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-
regarding-the-war-powers-report/.
275 Section III of the agreement states: “In order to strengthen security and stability in Iraq, and thereby contribute to
international peace and stability, and to enhance the ability of the Republic of Iraq to deter all threats against its
sovereignty, security, and territorial integrity, the Parties shall continue to foster close cooperation concerning defense
and security arrangements without prejudice to Iraqi sovereignty over its land, sea, and air territory.”
276 Brett McGurk (@brett_mcgurk), Twitter, January 8, 2020, 10:07 AM.
Congressional Research Service

48

U.S. Overseas Basing: Background and Issues for Congress

U.S. and coalition training efforts for various Iraqi security forces have been implemented at
different locations, including in the Kurdistan region, with U.S. training activities carried out
pursuant to the authorities granted by Congress for the Iraq Train and Equip Program and the
Office of Security Cooperation at the U.S. Embassy in Baghdad (OSC-I).277 OSC-I helps
administer training and support programs funded through Foreign Military Sales and Foreign
Military Financing assistance.278 Congress has authorized the continuation of train and equip
program activities through December 2024 and appropriated funding for related programs that
remains available through FY2024.

U.S. military capabilities in Iraq reportedly include AH-64E Apache helicopters, MH-47G
Chinook helicopters, MH-60M Black Hawk helicopters, and unmanned surveillance aircraft.279
Since October 2023, U.S. bases in Iraq have been subject to numerous attacks by non-state actors
in the region, and DOD has conducted strikes against targets in Iraq. For more information, see
CRS Insight IN12309, Iraq: Attacks and U.S. Strikes Reopen Discussion of U.S. Military
Presence, by Christopher M. Blanchard.
In December 2023, media reporting suggested that approximately 2,400 DOD personnel were
present in Iraq.280
Israel
DOD participates in joint exercises with the Israeli military to foster interoperability.281 DOD
maintains an emergency stockpile of weapons and equipment in Israel.282
According to DMDC, as of March 2024, 115 active-duty U.S. military servicemembers were
permanently assigned to Israel.283
Jordan
The Muwaffaq al Salti Air Base in Jordan reportedly hosts the headquarters of U.S. Air Forces
Central’s 332nd Air Expeditionary Wing.284 In July 2023, DOD reportedly deployed F-35s to the
base.285

277 Specific authority for the Iraq train and equip program is provided in Section 1236 of the FY2015 National Defense
Authorization Act (P.L. 113-291), as amended. OSC-I activities are authorized by Section 1215 of the FY2012
National Defense Authorization Act (P.L. 112-81), as amended.
278 See description in LIG-OCO, Report to Congress on Operation Inherent Resolve, January 1-March 31, 2020.
279 The Military Balance, IISS, p. 48, https://www.iiss.org/en/publications/the-military-balance/.
280 See J.P. Lawrence, “No U.S. Troops Injured in Latest Rocket Strike at Iraq Base,” Stars and Stripes, December 21,
2023.
281 U.S. Department of State, U.S. Security Cooperation with Israel, Fact Sheet, October 19, 2023,
https://www.state.gov/u-s-security-cooperation-with-israel/.
282 CRS Report RL33222, U.S. Foreign Aid to Israel, by Jeremy M. Sharp.
283 DMDC, “Military and Civilian Personnel by Service/Agency by State/Country,” March 2024, available for
download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
284 J.P. Lawrence, “Pentagon awards latest contract in $265 million project to expand remote air base in Jordan,” Stars
and Stripes, May 13, 2022, https://www.stripes.com/theaters/middle_east/2022-05-13/jordan-air-force-base-contract-
pentagon-5988272.html.
285 Jeremy Binnie, “US Air Force deploys F-35s to Jordan,” Janes, July 28, 2023, https://www.janes.com/defence-
news/news-detail/us-air-force-deploys-f-35s-to-jordan.
Congressional Research Service

49

U.S. Overseas Basing: Background and Issues for Congress

In 2021, DOD transferred a stockpile of weaponry and supplies from a military base in Qatar to
Jordan.286
In January 2024, U.S. Central Command reported that about 350 U.S. military personnel were
deployed to a location known as Tower 22.287 Tower 22 is reportedly located near the borders of
Iraq and Syria and close to the U.S. base at Al Tanf in Syria.288 A drone attack on Tower 22 killed
three U.S. servicemembers in January 2024.289
According to a December 2023 letter submitted by the Biden Administration to congressional
leaders regarding the War Powers Report, DOD had 3,188 military personnel in Jordan.”290 The
Biden Administration defines this mission as one “to support Defeat-[Islamic State] operations, to
enhance Jordan’s security, and to promote regional stability.”291
According to DMDC, as of March 2024, 120 active-duty U.S. military servicemembers were
permanently assigned to Jordan.292
Kuwait
Camp Arifjan hosts the forward headquarters of U.S. Army Central (USARCENT), the Army
component of CENTCOM.293 Task Force Spartan in Kuwait reportedly has included two brigades
and four battalion task forces, which provide capabilities including helicopter aviation, logistics
support, force protection, and information management.294 The Army maintains a stockpile of
prepositioned materiel in Kuwait.295 The Army pre-positioned stocks (APS) in Kuwait are
intended to outfit two combat Army brigades.296
At Ali Al-Salem Air Base, the U.S. Air Force’s 386th Air Expeditionary Wing is “the primary
airlift hub and gateway for delivering combat power to joint and coalition forces in the U.S.
Central Command [AOR].”297 U.S. Air Force capabilities in Kuwait include unmanned

286 J.P. Lawrence, “US military shifts Army basing from Qatar to Jordan in move that could provide leverage against
Iran,” Stars and Stripes, July 1, 2021, https://www.stripes.com/branches/army/2021-07-01/us-military-closes-qatar-
camps-in-move-that-could-play-into-iran-policy-2009140.html.
287 CENTCOM, “UPDATE: U.S. Casualties in Northeast Jordan, near Syrian Border,” January 28, 2024,
https://www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/3658552/update-us-casualties-in-
northeast-jordan-near-syrian-border/.
288 John Gambrell, “What is Tower 22, the military base that was attacked in Jordan where 3 US troops were killed?,”
The Associated Press, January 29, 2024, https://apnews.com/article/us-jordan-drone-attack-iran-tower-22-israel-hamas-
war-0265beed527e3009a966c0531c08838e.
289 Ibid.
290 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” December 7, 2023.
291 Ibid.
292 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
293 CENTCOM, “CENTCOM,” https://www.centcom.mil/ABOUT-US/COMPONENT-COMMANDS/.
294 Virginia National Guard, “29ID assumes authority of Task Force Spartan,” July 23, 2021,
https://va.ng.mil/News/Article/2705441/29id-assumes-authority-of-task-force-spartan/.
295 CRS In Focus IF11699, Defense Primer: Department of Defense Pre-Positioned Materiel, by Cameron M. Keys.
296 IISS, The Military Balance, p. 49, https://www.iiss.org/en/publications/the-military-balance/.
297 U.S. Air Force, “The 386th Air Expeditionary Wing,” https://www.afcent.af.mil/About/Mission/.
Congressional Research Service

50

U.S. Overseas Basing: Background and Issues for Congress

surveillance aircraft, including MQ-9 Reapers.298 DOD also has combat airlift capabilities in
Kuwait.299
The largest U.S. air logistics facility in the region is in Kuwait, at the country’s international
airport, Kuwait International Airport.300
According to DMDC, as of March 2024, about 533 active-duty U.S. military servicemembers
were permanently assigned to Kuwait.301 However, in July 2021 the U.S. Department of State
reported that approximately 13,500 U.S. servicemembers or personnel were based in Kuwait,
primarily at Camp Arifjan and Ali Al-Salem Air Base.302
Qatar
Al Udeid Air Base hosts the headquarters of CENTCOM Forward, U.S. Air Forces Central
Command (AFCENT) Forward, and U.S. Special Operations Command Central (SOCCENT)
Forward, as well as CENTCOM’s Combined Air Operations Center, the Combined Joint
Interagency Task Force – Syria, and the U.S. Air Force’s 379th Air Expeditionary Wing, one of
the largest expeditionary wings in the world.303 Since 2003, Qatar has contributed more than $8
billion in developing Al Udeid Air Base for use by the U.S. military.304 According to media
reports, DOD recently reached a defense cooperation agreement with Qatar that includes terms
extending U.S. use of Al Udeid by another ten years.305
DOD capabilities in Qatar reportedly include surveillance aircraft, tanker refueling (KC-135
Stratotankers), combat airlift (C-17A Globemasters, CH-130H Hercules), Patriot missile defense
systems, and AN/TPY-2 X-band radar to support missile defense systems.306 The base hosts a
rotational presence of combat aircraft.307

298 The Military Balance, IISS, p. 49, https://www.iiss.org/en/publications/the-military-balance/.
299 CENTCOM, “Joint Exercise Showcases Rapid Global Mobility In CENTCOM Theater,” August 13, 2022,
https://www.centcom.mil/MEDIA/NEWS-ARTICLES/News-Article-View/Article/3131417/joint-exercise-showcases-
rapid-global-mobility-in-centcom-theater/.
300 Bilal Y. Saab, “Beyond Post-Desert Storm: How to Elevate the US-Kuwait Security Partnership,” Middle East
Institute, September 14, 2022, https://www.mei.edu/publications/beyond-post-desert-storm-how-elevate-us-kuwait-
security-partnership.
301 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
302 U.S. Department of State, “U.S. Security Cooperation with Kuwait,” July 22, 2021, https://www.state.gov/u-s-
security-cooperation-with-kuwait-2/.
303 U.S. Department of State, “U.S. Security Cooperation with Qatar,” July 30, 2021, https://www.state.gov/u-s-
security-cooperation-with-qatar; and U.S. Air Force, “Fact Sheet,” https://www.afcent.af.mil/Units/379th-Air-
Expeditionary-Wing/Fact-Sheets/Display/Article/501479/379th-air-expeditionary-wing-fact-sheet/.
304 U.S. Department of State, “U.S. Security Cooperation with Qatar,” July 30, 2021, https://www.state.gov/u-s-
security-cooperation-with-qatar.
305 Jonathan Landay and Kanishka Singh, “US Reaches Deal To Extend Military Presence At Qatar Base - Source,”
Reuters, January 2, 2024, https://www.reuters.com/world/middle-east/us-reaches-deal-extend-military-presence-qatar-
base-source-2024-01-02/.
306 Ibid. Also see International Institute for Strategic Studies, The Military Balance, Indexes of Tables, Figures and
Maps, p. 49, https://www.iiss.org/en/publications/the-military-balance/.
307 U.S. Air Forces Central Command, “Hosting lethality: F-35s arrive at AUAB,” September 13, 2023,
https://www.afcent.af.mil/Units/379th-Air-Expeditionary-Wing/News/Display/Article/3523998/hosting-lethality-f-35s-
arrive-at-auab/.U.S and CENTCOM, “332nd, 379th AEWs work together to expand agile combat employment in
AOR,” August 28, 2020, https://www.centcom.mil/MEDIA/NEWS-ARTICLES/News-Article-
View/Article/2328501/332nd-379th-aews-work-together-to-expand-agile-combat-employment-in-aor/.
Congressional Research Service

51

U.S. Overseas Basing: Background and Issues for Congress

DOD also operates Camp As Sayliyah in Qatar, a former Army base that has been used as a U.S.
government processing center for Afghans seeking resettlement.308
According to DMDC, as of March 2024, about 303 active-duty U.S. military servicemembers
were permanently assigned to Qatar.309 However, media reports suggest there may be as many as
8,000 to 10,000 U.S. personnel operating in Qatar at any given time.310
Saudi Arabia
In June 2024, the White House stated that approximately 2,321 U.S. military personnel were in
Saudi Arabia.311 Most of these personnel appear to be stationed at Saudi Arabia’s Prince Sultan
Air Base (PSAB), which hosts the 378th Air Expeditionary Wing, a U.S. Air Force unit that—
according to U.S. Air Forces Central (AFCENT) as of October 2023—“supports approximately
2,200 airmen and soldiers assigned to PSAB, as well as the U.S. Army’s Patriot missile defense
capability and Terminal High Altitude Area Defense (THAAD) capability in the region.”312 Air
Force capabilities at PSAB include tanker refueling aircraft.313 PSAB hosts rotational
deployments of combat aircraft.314
Syria
In June 2024, the White House stated that “a small presence of United States Armed Forces
remains in strategically significant locations in Syria to conduct operations, in partnership with
local, vetted ground forces, to address continuing terrorist threats emanating from Syria.”315 The
U.S. military presence in Syria reportedly includes the base at Al Tanf and various facilities in
northeastern Syria.316 CENTCOM and DOD officials have also indicated a presence of U.S.

308 U.S. Department of State, “Secretary Antony J. Blinken Remarks to the Press,” November 22, 2022,
https://www.state.gov/secretary-antony-j-blinken-remarks-to-the-press-4/.
309 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
310 For open-source reports of higher numbers, see The Military Balance, IISS, p. 49; and “US Forces Monitor Mideast
Skies at Qatar Base Amid World Cup,” Voice of America, December 3, 2022, https://www.voanews.com/a/us-forces-
monitor-mideast-skies-at-qatar-base-amid-world-cup/6859727.html.
311 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
— War Powers Report,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/.
312 U.S. Air Force, “Changing of the Guard: 378th AEW Holds Change of Command Ceremony,” October 10, 2023,
https://www.afcent.af.mil/Units/378th-Air-Expeditionary-Wing/News/Article/3552119/changing-of-the-guard-378th-
aew-holds-change-of-command-ceremony/.
313 Unshin Lee Harpley, “KC-135s Arrive in Saudi Arabia to Replace Departed KC-10s,” Air and Space Forces
Magazine, October 17, 2023, https://www.airandspaceforces.com/kc-135s-saudi-arabia-replace-departed-kc-10s/.
314 See, for example, “Farewell to the Falcon: 457th EFS concludes last deployment flying the F-16,” U.S. Air Force,
August 9, 2023, https://www.afcent.af.mil/Units/378th-Air-Expeditionary-Wing/News/Article/3487919/farewell-to-
the-falcon-457th-efs-concludes-last-deployment-flying-the-f-16/.
315 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
— War Powers Report,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/.
316 Rachel Nostrant, “A Secretive US Special-Operations Base in Syria Is Taking Fire from a Shadowy Middle East
War,” Military.com, November 2, 2022, https://www.military.com/daily-news/2022/11/02/secretive-us-special-
operations-base-syria-taking-fire-shadowy-middle-east-war. See also “U.S. Responds to Attack That Killed U.S.
Contractor in Syria,” DOD, March 24, 2023, https://www.defense.gov/News/News-Stories/Article/Article/3341127/us-
responds-to-attack-that-killed-us-contractor-in-syria/.
Congressional Research Service

52

U.S. Overseas Basing: Background and Issues for Congress

forces at the Rumalyn Landing Zone, Mission Support Site Conoco, Mission Support Site
Euphrates, Mission Support Site Green Village, and at Patrol Base Shaddadi, all in northeast
Syria.317
U.S. forces in Syria conduct counterterror missions against the Islamic State group and Al Qaeda-
affiliated militants, and are equipped to defend themselves against Iran-backed militias that have
attacked U.S. facilities.318 They also advise and assist the Syrian Democratic Forces, on missions
that include securing detention facilities holding Islamic State personnel.319
The commander of U.S. Central Command said in March 2023 that there were approximately 900
servicemembers deployed to Syria, according to CENTCOM.320
United Arab Emirates
Al Dhafra Air Base hosts the Air Force’s 380th Air Expeditionary Wing, which includes
surveillance aircraft such as MQ-9 Reapers.321 Air Force capabilities in the UAE also reportedly
include airborne early warning and control (AEW&C) aircraft; ISR aircraft; and tanker refueling
aircraft.322 Al Dhafra hosts rotations of combat aircraft units; in 2022, the Air Force deployed F-
22 Raptors to the UAE.323 In April 2023, the Air Force deployed A-10 Thunderbolts to the
UAE.324
Al Dhafra hosts the Gulf Air Warfare Center, which provides regionally focused air and missile
defense training for around 2,000 participants from 10 nations every year.325 The UAE-owned
Port of Jebel Ali and other UAE ports provide logistical support for the U.S. Navy and
collectively host more Navy ships than any other port outside the United States.326

317 CENTCOM, “Rocket Attack Targeted US and Partnered Forces in Syria Fails,” October 8, 2023,
https://www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/3183695/rocket-attack-targeted-us-
and-partnered-forces-in-syria-fails/. “Two Rockets Target Coalition Forces,” CENTCOM, January 4, 2023,
https://www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/3258231/two-rockets-target-
coalition-forces/. “Pentagon Press Secretary Air Force Maj. Gen. Pat Ryder Holds a Press Briefing,” DOD, February 5,
2024, https://www.defense.gov/News/Transcripts/Transcript/Article/3667341/pentagon-press-secretary-air-force-maj-
gen-pat-ryder-holds-a-press-briefing/.
318 The Associated Press, “A look at the US military mission in Syria and its dangers,” March 24, 2023,
https://apnews.com/article/syria-us-troops-drone-attack-6194dca97f594e3609914637463c4ce3.
319 Ibid.
320 Remarks made by CENTCOM commander General Michael “Erik” Kurilla in House Armed Services Committee
hearing, “U.S. Military Posture and National Security Challenges in the Greater Middle East and Africa, March 23,
2023.Video available at https://armedservices.house.gov/hearings/full-committee-hearing-us-military-posture-and-
national-security-challenges-greater-middle (remarks start at 2:25:30).
321 U.S. Air Forces Central Command, “380th Air Expeditionary Wing,” July 2021,
https://www.afcent.af.mil/Units/380th-Air-Expeditionary-Wing/Fact-Sheets/Article/445043/380th-air-expeditionary-
wing/.
322 International Institute for Strategic Studies, The Military Balance, Indexes of Tables, Figures and Maps, p. 49,
https://www.iiss.org/en/publications/the-military-balance/.
323 Greg Hadley, “What F-22s Arriving in UAE Can Offer After Recent Iranian-Backed Houthi Attacks,” Air and
Space Forces Magazine , February 15, 2022, https://www.airandspaceforces.com/what-f-22s-arriving-in-uae-can-offer-
after-recent-iranian-backed-houthi-attacks/.
324 U.S. Air Forces Central Command, “First A-10 sortie for 75 EFS generated at Al Dhafra AB,” press release, April 6,
2023, https://www.afcent.af.mil/Units/380th-Air-Expeditionary-Wing/News/Display/Article/3354174/first-a-10-sortie-
for-75-efs-generated-at-al-dhafra-ab/.
325 U.S. Department of State, “U.S. Security Cooperation with the United Arab Emirates,” July 25, 2021,
https://www.state.gov/u-s-security-cooperation-with-the-united-arab-emirates/.
326 Ibid.
Congressional Research Service

53

U.S. Overseas Basing: Background and Issues for Congress

In early 2022, Al Dhafra Air Base was targeted by missile attacks from Yemen.327
U.S. officials have raised concerns about UAE ties to China and Russia.328
In February 2024, UAE reportedly placed restrictions on DOD’s use of military bases located in
UAE for launching retaliatory airstrikes on Iranian proxies.329
According to DMDC, as of March 2024, about 177 active-duty U.S. military servicemembers
were permanently assigned to U.A.E..330 As of July 2021, the U.S. Department of State reported
that about 3,500 servicemembers were based in U.A.E.331
Yemen
In December 2023, the Biden Administration reported to Congress that "a small number" of U.S.
military personnel “are deployed to Yemen to conduct operations against al-Qa'ida in the Arabian
Peninsula and ISIS.”332 Information about the location of those servicemembers is not publicly
available.
Africa
U.S. overseas basing in Africa is established and governed by bilateral executive agreements
(e.g., DCAs/EDCAs, MOUs). Most of the U.S. servicemembers permanently assigned to this
region are stationed at persistent bases in Djibouti. As in the Middle East, most U.S.
servicemembers present in Africa appear to be on temporary or rotational assignments, and are
thus not accounted for by DMDC’s figures. To reflect this, throughout this section CRS has
supplemented DMDC-provided figures (which only include permanently-assigned
servicemembers) with reporting or estimates from other sources, as appropriate.
Djibouti
Djibouti hosts Camp Lemonnier and Chabelley Airfield. Camp Lemonnier was first occupied by
U.S. forces in 2002 and serves as the headquarters for Combined Joint Task Force – Horn of
Africa, which conducts regional operations to “enhance partner nation capacity, promote regional
stability, dissuade conflict, and protect U.S. and coalition interests.”333 The base is located near
the Bab al-Mandab Strait and supports operations in the Red Sea and beyond.334 In addition, since

327 CRS Insight IN11891, Attacks Against the United Arab Emirates: Issues for Congress.
328 Ibid.
329 Lara Seligman, Alexander Ward, and Nahal Toosi, “UAE restricts US ability to launch retaliatory airstrikes against
Iran proxies,” Politico, February 14, 2024, https://www.politico.com/news/2024/02/14/united-arab-emirates-retaliatory-
airstrikes-iran-00141460.
330 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
331 U.S. Department of State, “U.S. Security Cooperation with the United Arab Emirates,” June 25, 2021,
https://www.state.gov/u-s-security-cooperation-with-the-united-arab-emirates/.
332 The White House, Letter to the Speaker of the House and President Pro Tempore of the Senate Regarding the War
Powers Report, December 7, 2023, https://www.whitehouse.gov/briefing-room/presidential-actions/2023/12/07/letter-
to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-regarding-the-war-powers-
report/
333 AFRICOM, “Combined Joint Task Force – Horn of Africa,” https://www.africom.mil/our-team/combined-joint-
task-force---horn-of-africa.
334 Bruno Maçães, “The strait at the center of the world”, Politico, January 29, 2018, https://www.politico.eu/blogs/the-
coming-wars/2018/01/the-strait-at-the-center-of-the-world/.
Congressional Research Service

54

U.S. Overseas Basing: Background and Issues for Congress

2013 Djibouti has hosted Chabelley Airfield, which the Air Force describes as its “largest
remotely piloted aircraft base in Africa.”335
According to DMDC, approximately 406 active-duty servicemembers were permanently assigned
to Djibouti as of March 2024.336 However, according to the Navy, Camp Lemonnier supports
“approximately 4,000 U.S., joint, and allied forces military and civilian personnel.”337
Gabon
Gabon hosts a cooperative security location in the capital of Libreville.338 According to the U.S.
State Department, access to this base contributes to “enabling the projection of forces in central
and southern Africa”.339
According to DMDC, approximately 12 active-duty servicemembers were permanently assigned
to Gabon as of March 2024.340
Kenya
Kenya hosts U.S. forces at Manda Bay, a cooperative security location along the country’s eastern
coast.341 According to DOD, Manda Bay is used to “provide training to African partners, respond
to crises and protect U.S. interests,” and base operations are managed by the U.S. Air Force.342 In
2020, Manda Bay was attacked by al-Shabaab militants, leading to the deaths of one U.S. soldier
and two U.S. contract personnel.343 DOD’s Base Structure Report and AFRICOM also identify
Mombasa as the site of a cooperative security location.344
According to DMDC, approximately 65 active-duty servicemembers were permanently assigned
to Kenya as of March 2024.345

335 Tech. Sgt. Jayson Burns, “Chabelley Airfield Celebrates 10-year Anniversary,” U.S. Air Force, March 28, 2023,
https://www.usafe.af.mil/News/Article-Display/Article/3342622/chabelley-airfield-celebrates-10-year-anniversary/.
336 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
337 U.S. Navy, “Installation Information,” https://cnreurafcent.cnic.navy.mil/Installations/Camp-Lemonnier-Djibouti/.
Rion Codrington, “Partner Appreciation Day Celebrates 21 Days of Partnership at Camp Lemonnier,” U.S. Navy,
November 8, 2023 https://cnreurafcent.cnic.navy.mil/Installations/Camp-Lemonnier-
Djibouti/News/Article/3587466/partner-appreciation-day-celebrates-21-years-of-partnership-at-camp-lemonnier/.
338 U.S. Department of State, “Integrated Country Strategy – Gabon,” May 16, 2022, p. 1, https://www.state.gov/wp-
content/uploads/2022/07/ICS_AF_Gabon_Public.pdf.
339 Ibid.
340 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
341 Tech. Sgt. Dhruv Gopinath, “CSL Manda Bay welcomes SECDEF, Kenya Defence Force leaders,” U.S. Air Forces
in Europe & Air Forces Africa,” September 29, 2023 https://www.usafe.af.mil/Units/435th-Air-Expeditionary-
Wing/News/Article/3542164/csl-manda-bay-welcomes-secdef-kenya-defence-force-leaders/.
342 Department of Defense, “Independent Review into Jan 5, 2020 al-Shabaab Attack at Manda Bay, Kenya,” March
10, 2022, https://www.defense.gov/News/Releases/Release/Article/2962655.
343 Ibid.
344 Department of Defense, FY2023 Base Structure Report, https://www.acq.osd.mil/eie/BSI/BEI_Library.html.
345 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

55

U.S. Overseas Basing: Background and Issues for Congress

Niger
Prior to April 2024, Niger hosted U.S. forces at multiple locations in the country, including two
bases known as Air Base 101 (located near the capital, Niamey) and Air Base 201 (located in the
city of Agadez). According to DOD, these sites supported counterterrorism operations and
security assistance activities.346 However, following a 2023 coup d’état, the U.S. Department of
State announced the suspension of economic and military aid to Niger, and in March 2024 the
Nigerien government announced the termination of its SOFA with the United States.347 In May
2024, the Biden Administration announced that U.S. forces would withdraw from the country by
September 15, 2024.348
According to DMDC, approximately 72 active-duty servicemembers were permanently assigned
to Niger as of March 2024.349 As of June 2024, the White House stated that “approximately 700
United States military personnel are currently deployed to Niger… however, the Department of
Defense is in the process of withdrawing United States military personnel from Niger, and the
withdrawal will be completed over the next several months.”350
British Overseas Territory of Saint Helena, Ascension Island, and Tristan da
Cunha (Ascension Island)
Ascension Island, part of the British Overseas Territory of Saint Helena, Ascension Island, and
Tristan da Cunha, hosts U.S. Air Force and Space Force facilities and personnel at Ascension
Island Auxiliary Airfield. AFRICOM has stated that this base is one of two “enduring Forward
Operating Sites in Africa” (the other being Camp Lemonnier).351 According to the Space Force, in
2023 DOD completed a “$352.6 million, full-depth rebuild of the remote runway” at the base.352
DOD has stated that its presence at Ascension Island supports air logistics operations and space
launch tracking.353

346 C. Todd Lopez, “U.S. Resumes ISR Flight Operations in Niger,” DOD News, September 14, 2023.
347 See CRS In Focus IF12464, Niger.
348 Eric Schmitt, “U.S. and Niger Announce Withdrawal of American Personnel by September,” The New York Times,
May 19, 2024.
349 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
350 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/.
351 Statement of General Michael E. Langley before the Senate Armed Services Committee,” March 16, 2023,
https://www.africom.mil/document/35173/africom-cleared-fy24-sasc-posture-hearing-16-mar-2023pdf.
352 U.S. Air Force, “AFIMSC completes largest runway construction project in years,” May 10, 2023,
https://www.patrick.spaceforce.mil/News/Article-Display/Article/3391377/afimsc-completes-largest-runway-
construction-project-in-years/.
353 U.S. Air Force, “Atlantic runway reopens, increases U.S., British military capabilities,” September 8, 2022,
https://www.afimsc.af.mil/News/Article-Display/Article/3152849/atlantic-runway-reopens-increases-us-british-
military-capabilities/; and “Small island, big mission – Ascension Island supports 45 SW,” U.S. Space Force, February
6, 2019, at https://www.patrick.spaceforce.mil/News/Article-Display/Article/1749916/small-island-big-mission-
ascension-island-supports-45-sw/.
Congressional Research Service

56

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately three active-duty servicemembers were permanently
assigned to the “British Atlantic Ocean Territory” (which appears to be identical with the British
Overseas Territory of Saint Helena, Ascension Island, and Tristan da Cunha) as of March 2024.354
Senegal
Senegal provides U.S. forces with access “for exclusive use” to Captain Andalla Cissé Air Base
(located in the capital, Dakar), as well as access “for joint use” to Thiès Air Base (located in the
town of Thiès) and Admiral Faye Gassama Naval Base (located in Dakar).355 According to the
U.S. State Department, access to these facilities supports U.S. operations in the region, which
may include security assistance activities as well as humanitarian response, evacuation support, or
logistical activities.356
According to DMDC, approximately 22 active-duty servicemembers were permanently assigned
to Senegal as of March 2024.357
Somalia
According to DOD, Somalia hosts “a small, persistent U.S. military presence” that supports the
“training, advising and equipping [of] partner forces to five them the tools they need to disrupt,
degrade and monitor al-Shabab."358 The locations at which these forces are deployed are unclear
from publicly available sources, but Baledogle and Kismayo have been identified by U.S.
government sources as locations hosting indeterminate numbers of U.S. troops.359 In June 2024,
the White House stated that “United States military personnel conduct periodic engagements in
Somalia to train, advise, and assist regional forces, including Somali and African Union
Transition Mission in Somalia forces, in connection with counterterrorism operations.”360

354 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
355 U.S. Department of State, “Agreement between the United States of America and the Republic of Senegal on
Defense Cooperation,” May 2016, https://www.state.gov/wp-content/uploads/2019/02/16-812-Senegal-Defense-
Cooperation.pdf.
356 U.S. Department of State, “Integrated Country Strategy—Senegal,” April 11, 2022, pp. 9-10,
https://www.state.gov/wp-content/uploads/2022/06/ICS_AF_Senegal_Public.pdf.
357 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
358 According to DOD, U.S. forces in Somalia were not directly engaging in combat operations as of May 2022. C.
Todd Lopez, “U.S. to Resume Small, Persistent Presence in Somalia,” DOD News, May 16, 2022,
https://www.defense.gov/News/News-Stories/Article/Article/3033345/us-to-resume-small-persistent-presence-in-
somalia/.
359 Master Sgt. Brok McCarthy, “Fallen Soldier Memorialized at Contingency Locations,” AFRICOM, June 2, 2020, at
https://www.africom.mil/article/32903/; and “June 21, 2023 Press Release,” U.S. Embassy Somalia, June 21, 2023,
https://so.usembassy.gov/africom-command-gen-langley-visits-somalia/.
360 The White House, “Letter to the Speaker of the House of Representatives and President pro tempore of the Senate
regarding the War Powers Report,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/.
Congressional Research Service

57

U.S. Overseas Basing: Background and Issues for Congress

According to DMDC, approximately 60 active-duty servicemembers were permanently assigned
to Somalia as of March 2024.361 However, media reports suggest the total number of U.S.
servicemembers present in Somalia may be between 100 and 500.362
Latin America and the Caribbean
U.S. overseas basing in Latin America and the Caribbean is established and governed by bilateral
executive agreements (DCAs/EDCAs, MOUs, Strategic Framework Agreements, etc.)—except in
the case of Cuba, where U.S. forces are present pursuant to diplomatic agreements that the current
Cuban government does not consider legitimate.363
Aruba and Curaçao (Constituent Countries of the Netherlands)
Aruba hosts a cooperative security location at its Reina Beatrix International Airport, and Curaçao
hosts a cooperative security location at its Hato International Airport.364 Both bases are managed
by the Air Force and support counter-narcotics missions.365 Aruba and Curaçao are each
constituent countries of the Kingdom of the Netherlands, meaning that the Dutch government
handles their foreign and defense policies.366
According to DMDC, no active-duty servicemembers were permanently assigned to Aruba or
Curaçao as of March 2024.367
The Bahamas
The United States maintains the Atlantic Undersea Test and Evaluation Center (AUTEC) in the
Bahamas. AUTEC primarily supports U.S. Navy research, development, test, and evaluation
activities, particularly those relating to submarine and anti-submarine warfare, and includes a
number of underwater and “in-air” test facilities.368
According to DMDC, 63 active-duty servicemembers were permanently assigned to the Bahamas
as of March 2024.369

361 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
362 Charlie Savage and Eric Schmitt, “Biden Approves Plan to Redeploy Several Hundred Ground Forces Into
Somalia,” The New York Times, May 16, 2022, https://www.nytimes.com/2022/05/16/us/politics/biden-military-
somalia.html.
363 For more information, refer to the entry for “Cuba” below.
364 SOUTHCOM appears to sometimes refer to both sites as a single cooperative security location, although they are
located in different countries.
365 U.S. Consulate in Curaçao, “U.S. Cooperative Security Location Welcomes New Commander,” June 27, 2023,
https://cw.usconsulate.gov/u-s-cooperative-security-location-welcomes-new-commander/.
366 Government of the Netherlands, “Responsibilities of the Netherlands, Aruba, Curaçao and St Maarten,”
https://www.government.nl/topics/caribbean-parts-of-the-kingdom/responsibilities-of-the-netherlands-aruba-curacao-
and-st-maarten.
367 DMDC’s March 2024 report lists Aruba and Curaçao as the “Netherlands Antilles.” Defense Manpower Data
Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March 2024, available for download at
https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
368 U.S. Navy, “AUTEC Information,” https://www.navsea.navy.mil/NUWC_Newport/AUTEC/. See also “Atlantic
Undersea Test and Evaluation Center (AUTEC) Backgrounder,” Holland & Knight LLP (on behalf of the government
of the Bahamas), 2022, https://efile.fara.gov/docs/3718-Informational-Materials-20220722-7.pdf.
369 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

58

U.S. Overseas Basing: Background and Issues for Congress

Cuba
The United States maintains Naval Station Guantanamo Bay in Cuba. The base includes a facility
that has been used to detain U.S. military prisoners, including some captured during the Global
War on Terror; according to the Navy, it also “support[s] unified, inter-agency joint operations,
and training.”370 Compared to other overseas basing relationships, that between the United States
and Cuba is unique. The U.S. government holds that DOD’s presence at Guantanamo Bay is
authorized by diplomatic agreements (two 1903 executive agreements and one 1934 treaty)
concluded prior to the 1958 Cuban Revolution, while the current Cuban government views these
as illegitimate and claims that the United States “illegally occupies” the base.371
According to DMDC, 616 active-duty servicemembers were permanently assigned to Cuba as of
March 2024.372
El Salvador
El Salvador hosts Cooperative Security Location Comalapa, a Navy base located in Comalapa, El
Salvador. According to SOUTHCOM, it supports efforts to combat transnational organized crime,
particularly the detection and interdiction of illegal narcotics.373
According to DMDC, 54 active-duty servicemembers were permanently assigned to El Salvador
as of March 2024.374
Honduras
Honduras hosts Soto Cano Air Base, an Army base located in near the town of Comayagua.
According to SOUTHCOM, it is the only forward operating site in Central and South America.375
Soto Cano supports Joint Task Force-Bravo, a SOUTHCOM task force intended to “counter
transnational organized crime, [provide] humanitarian assistance/disaster relief efforts and the
development of partner capacities, [and promote regional cooperation and security in Central

370 According to a letter sent by the Biden Administration to congressional leaders in June 2024, Guantanamo Bay held
30 detainees. The White House, “Letter from Joseph Biden, President of the United States, to Speaker of the House and
President pro tempore of the Senate,” June 7, 2024, https://www.whitehouse.gov/briefing-room/presidential-
actions/2024/06/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-war-
powers-report/U.S. Navy, “Naval Station Guantanamo Bay - Mission and Vision,”
https://cnrse.cnic.navy.mil/Installations/NS-Guantanamo-Bay/About/Mission-and-Vision/.
371 For more information, see CRS Report R44137, Naval Station Guantanamo Bay: History and Legal Issues
Regarding Its Lease Agreements. For reporting on the Cuban government’s position, see Dan Lamothe and Thomas
Gibbons-Neff, “Cuba Wants Back the ‘Illegally Occupied’ Base at Guantanamo,” The Washington Post, March 21,
2016, https://www.washingtonpost.com/news/checkpoint/wp/2016/03/21/cuba-wants-back-the-illegally-occupied-base-
at-guantanamo-the-u-s-isnt-budging/.
372 The White House, “Letter from Joseph Biden, President of the United States, to Speaker of the House and President
pro tempore of the Senate,” December 7, 2023, https://www.whitehouse.gov/briefing-room/presidential-
actions/2023/12/07/letter-to-the-speaker-of-the-house-of-representatives-and-president-pro-tempore-of-the-senate-
regarding-the-war-powers-report/..
373 U.S. SOUTHCOM, “Cooperative Security Locations,” https://www.southcom.mil/Media/Special-
Coverage/Cooperative-Security-Locations/.
374 DMDC’s December 2023 report lists Aruba and Curaçao as the “Netherlands Antilles.” Defense Manpower Data
Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March 2024, available for download at
https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
375 “Army Support Activity – Soto Cano,” U.S. SOUTHCOM, https://www.jtfb.southcom.mil/Units/Army-Support-
Activity/.
Congressional Research Service

59

U.S. Overseas Basing: Background and Issues for Congress

America, South America and the Caribbean.”376 The 1st Battalion, 228th Aviation Regiment
operates from Soto Cano with assets including UH-60L Black Hawk, CH-47F Chinook, and
MEDEVAC HH-60L helicopters.377
According to DMDC, 365 active-duty U.S. servicemembers were permanently assigned to
Honduras as of March 2024.378

376 U.S. SOUTHCOM, “Joint Task Force-Bravo: About Us,” https://www.jtfb.southcom.mil/Home/About-Us/.
377 U.S. SOUTHCOM, “1-228th Aviation Regiment,” https://www.jtfb.southcom.mil/Units/1-228th-Aviation-
Regiment/.
378 Defense Manpower Data Center, “Military and Civilian Personnel by Service/Agency by State/Country,” March
2024, available for download at https://dwp.dmdc.osd.mil/dwp/app/dod-data-reports/workforce-reports.
Congressional Research Service

60

link to page 69 U.S. Overseas Basing: Background and Issues for Congress

Appendix B. Selected U.S. Overseas Bases
Table B-1. Selected U.S. Overseas Bases
Overseas Bases Covered by this Report
Persistent U.S.
No.
Base
Country/Territory
Region
Military Presence?a
1
U.S. Army Garrison Kwajalein Atol
Marshall Islands
Indo-Pacific
Yes
2
Camp Zama
Japan
Indo-Pacific
Yes
3
Shariki Communications Site
Japan
Indo-Pacific
No
4
Kyogamisaki Communications Site
Japan
Indo-Pacific
No
5
U.S. Fleet Activities Yokosuka
Japan
Indo-Pacific
Yes
6
U.S. Fleet Activities Sasebo
Japan
Indo-Pacific
Yes
7
Naval Air Facility Atsugi
Japan
Indo-Pacific
Yes
8
Marine Corps Air Station Iwakuni
Japan
Indo-Pacific
Yes
9
Yokota Air Base
Japan
Indo-Pacific
Yes
10
Misawa Air Base
Japan
Indo-Pacific
Yes
11
Kure Pier 6
Japan
Indo-Pacific
Yes
12
U.S. Army Garrison Okinawa
Japan
Indo-Pacific
Yes
13
U.S. Fleet Activities Okinawa
Japan
Indo-Pacific
Yes
14
Marine Corps Base Camp Butler
Japan
Indo-Pacific
Yes
15
Marine Corps Air Station Futenma
Japan
Indo-Pacific
Yes
16
Kadena Air Base
Japan
Indo-Pacific
Yes
17
Camp Humphreys
South Korea
Indo-Pacific
Yes
18
Army Garrison Daegu
South Korea
Indo-Pacific
Yes
19
Army Garrison Yongsan-Casey
South Korea
Indo-Pacific
Yes
20
Fleet Activities Chinhae
South Korea
Indo-Pacific
Yes
21
Marine Corps Installation Camp
South Korea
Indo-Pacific
No
Mujuk
22
Osan Air Base
South Korea
Indo-Pacific
Yes
23
Kunsan Air Base
South Korea
Indo-Pacific
Yes
24
Command Post Tango
South Korea
Indo-Pacific
Yes
25
Antonio Bautista Air Base
The Philippines
Indo-Pacific
No
26
Basa Air Base
The Philippines
Indo-Pacific
No
27
Fort Magsaysay
The Philippines
Indo-Pacific
No
28
Lumbia Airport
The Philippines
Indo-Pacific
No
29
Benito Ebuen Air Base
The Philippines
Indo-Pacific
No
30
Naval Base Camilo Osias
The Philippines
Indo-Pacific
No
31
Lal-lo Airport
The Philippines
Indo-Pacific
No
32
Camp Melchor Dela
The Philippines
Indo-Pacific
No
Congressional Research Service

61

link to page 69 U.S. Overseas Basing: Background and Issues for Congress

Persistent U.S.
No.
Base
Country/Territory
Region
Military Presence?a
33
Balabac Island
The Philippines
Indo-Pacific
No
34
Navy Region Center Singapore
Singapore
Indo-Pacific
Yes
35
Robertson Barracks
Australia
Indo-Pacific
No
36
RAAF Base Darwin
Australia
Indo-Pacific
No
37
RAAF Base Tindal
Australia
Indo-Pacific
No
38
NCS Harold E. Holt
Australia
Indo-Pacific
Yes
39
Momote Airport
Papua New Guinea
Indo-Pacific
No
40
Lombrum Naval Base
Papua New Guinea
Indo-Pacific
No
41
Nadzab Airport
Papua New Guinea
Indo-Pacific
No
42
Lae Seaport
Papua New Guinea
Indo-Pacific
No
43
Port Moresby Jacksons Int’l Airport
Papua New Guinea
Indo-Pacific
No
and Seaport
44
Naval Support Facility Diego Garcia
British Indian Ocean
Indo-Pacific
Yes
Territory (United
Kingdom)
45
Pituffik Space Base
Greenland (Denmark) Europe
Yes
46
Naval Air Station Keflavik
Iceland
Europe
Yes
47
Joint Warfare Center
Norway
Europe
Yes
48
RAF Lakenheath
United Kingdom
Europe
Yes
49
RAF Mildenhall
United Kingdom
Europe
Yes
50
RAF Alconbury/Molesworth
United Kingdom
Europe
Yes
51
RAF Croughton
United Kingdom
Europe
Yes
52
RAF Menwith Hil
United Kingdom
Europe
Yes
53
U.S. Army Garrison Benelux
Belgium
Europe
Yes
54
Kleine Brogel Air Base
Belgium
Europe
Yes
55
U.S. Army Garrison Stuttgart
Germany
Europe
Yes
56
U.S. Army Garrison Ansbach
Germany
Europe
Yes
57
U.S. Army Garrison Bavaria
Germany
Europe
Yes
58
U.S. Army Garrison Wiesbaden
Germany
Europe
Yes
59
Spangdahlem Air Base
Germany
Europe
Yes
60
Ramstein Air Base
Germany
Europe
Yes
61
Geilenkirchen Air Base
Germany
Europe
Yes
62
USAG Vicenza
Italy
Europe
Yes
63
Camp Darby
Italy
Europe
Yes
64
Naval Support Activity Naples
Italy
Europe
Yes
65
Naval Support Activity Naples
Italy
Europe
Yes
Detachment Gaeta
66
Naval Air Station Sigonella
Italy
Europe
Yes
Congressional Research Service

62

link to page 69 U.S. Overseas Basing: Background and Issues for Congress

Persistent U.S.
No.
Base
Country/Territory
Region
Military Presence?a
67
Ghedi Air Base
Italy
Europe
Yes
68
Aviano Air Base
Italy
Europe
Yes
69
Naval Station Rota
Spain
Europe
Yes
70
Morón Air Base
Spain
Europe
Yes
71
Lajes Field
Portugal
Europe
Yes
72
Naval Support Facility Redzikowo
Poland
Europe
No
73
Camp Kosciuszko
Poland
Europe
No
74
Żagań
Poland
Europe
No
75
Powidz Air Base
Poland
Europe
No
76
Lask Air Base
Poland
Europe
No
77
Camp Herkus
Lithuania
Europe
No
78
Šiauliai Air Base
Lithuania
Europe
No
79
Lielvārde Air Base
Latvia
Europe
No
80
Ämari Air Base
Estonia
Europe
No
81
Pápa Air Base
Hungary
Europe
No
82
Kecskemét Air Base
Hungary
Europe
No
83
Camp Turzi
Romania
Europe
No
84
Naval Support Facility Deveselu
Romania
Europe
No
85
Mihail Kogalniceanu Air Base
Romania
Europe
No
86
Novo Selo Training Area
Bulgaria
Europe
No
87
Graf Ignatievo Air Base
Bulgaria
Europe
No
88
Camp Bondsteel
Kosovo
Europe
Yes
89
Larissa Air Base
Greece
Europe
No
90
Stefanovikeio Air Base
Greece
Europe
No
91
Naval Support Activity Souda Bay
Greece
Europe
Yes
92
Izmir Air Station
Turkey
Europe
Yes
93
Incirlik Air Base
Turkey
Europe
Yes
94
RAF Akrotiri
Cyprus
Europe
No
95
Camp Arifjan
Kuwait
Middle East &
Yes
Central Asia
96
Camp Buehring
Kuwait
Middle East &
Yes
Central Asia
97
Al Jaber Air Base
Kuwait
Middle East &
Yes
Central Asia
98
Al Mubarak Air Base
Kuwait
Middle East &
Yes
Central Asia
99
Ali Al Salem Air Base
Kuwait
Middle East &
Yes
Central Asia
Congressional Research Service

63

link to page 69 U.S. Overseas Basing: Background and Issues for Congress

Persistent U.S.
No.
Base
Country/Territory
Region
Military Presence?a
100
Al Udeid Air Base
Qatar
Middle East &
Yes
Central Asia
101
Al Dhafra Air Base
United Arab Emirates
Middle East &
Yes
Central Asia
102
Jebel Ali
United Arab Emirates
Middle East &
No
Central Asia
103
King Faisal Air Base
Saudi Arabia
Middle East &
No
Central Asia
104
Prince Sultan Air Base
Saudi Arabia
Middle East &
No
Central Asia
105
Muwaffaq Salti Air Base
Jordan
Middle East &
No
Central Asia
106
Naval Support Activity Bahrain
Bahrain
Middle East &
Yes
Central Asia
107
Sheikh Isa Air Base
Bahrain
Middle East &
No
Central Asia
108
Erbil Air Base
Iraq
Middle East &
No
Central Asia
109
Al Asad Air Base
Iraq
Middle East &
No
Central Asia
110
Al Tanf Garrison
Syria
Middle East &
No
Central Asia
111
Rumalyn
Syria
Middle East &
No
Central Asia
112
Duqm
Oman
Middle East &
No
Central Asia
113
MFO South Camp
Egypt
Middle East &
No
Central Asia
114
Camp Lemonnier
Djibouti
Africa
Yes
115
Chabelley Airfield
Djibouti
Africa
No
116
Baledogle
Somalia
Africa
No
117
Mogadishu
Somalia
Africa
No
118
Kismayo
Somalia
Africa
No
119
Manda Bay
Kenya
Africa
No
120
Mombasa
Kenya
Africa
No
121
N’djamena
Chad
Africa
No
122
Ascension Island Auxiliary Airfield
British Overseas
Africa
Yes
Territory of Saint
Helena, Ascension
Island, and Tristan da
Cunha
123
Atlantic Undersea Test and
Bahamas
Latin America & Yes
Evaluation Center
the Caribbean
Congressional Research Service

64

link to page 69 U.S. Overseas Basing: Background and Issues for Congress

Persistent U.S.
No.
Base
Country/Territory
Region
Military Presence?a
124
Guantanamo Bay
Cuba
Latin America & Yes
the Caribbean
125
Soto Cano Air Base
Honduras
Latin America & Yes
the Caribbean
126
Cooperative Security Location
El Salvador
Latin America & No
Comalapa
the Caribbean
127
Cooperative Security Location Reina Aruba
Latin America & No
Beatrix International Airport
the Caribbean
128
Cooperative Security Location Hato
Curaçao
Latin America & No
International Airport
the Caribbean
Source: CRS analysis, for additional information see “Methodology” section of this report.
Notes:
a. Defined as continuous DOD use/control for least 15 years (for more information, refer to the “Overview
and Methodology” section of this report).

Congressional Research Service

65

U.S. Overseas Basing: Background and Issues for Congress

Appendix C. DOD Definitions and Methodological
Issues
DOD divides its overseas bases into two broad categories: enduring locations, which support U.S.
military activities on an ongoing basis, and contingency locations, which provide temporary
support for combat missions and other contingency operations.379 Enduring locations fall into one
of three categories, depending on the degree of U.S. presence:
• Main operating base. Defined by DOD as “a facility outside the United States and its
territories with permanently stationed operating forces and robust infrastructure.”380
• Forward operating site. Defined by DOD as “a scalable location outside the United
States and its territories intended for rotational use by operating forces.”381
• Cooperative security location. Defined by DOD as “a facility located outside the United
States and its territories with little or no permanent United States presence that is
maintained by periodic Service, contractor, or host nation support.”382
Similarly, DOD sorts its contingency locations into categories based on the timeframe of their
intended use: (1) initial locations (immediate need); (2) temporary locations (1-24 months); or (3)
semipermanent locations (24-60 months).383
Despite these official definitions, in practice there exists some ambiguity in the ways DOD and
other U.S. government (USG) organizations consider overseas basing. The distinctions between
DOD’s three categories of enduring locations are sometimes unclear. For instance, although the
department’s definition of forward operating sites states that they support “rotational use,” senior
officials have also indicated that some individual forward operating sites support a “permanent”
presence of U.S. forces.384 Additionally, DOD’s official taxonomy does not appear to be
consistently used across the department. For instance, although DOD defines a cooperative
security location as a type of enduring location located outside U.S. territory (and thus, an
overseas base), some DOD organizations have published material suggesting that cooperative
security locations should not be considered overseas bases.385 Officially defined terms may also

379 Chairman of the Joint Chiefs of Staff, “Joint Publication 4-04,” January 2019, p. vii,
https://www.jcs.mil/Portals/36/Documents/Doctrine/pubs/jp4_04.pdf. In addition, 10 U.S.C. §2687a defines enduring
locations and contingency locations in language consistent with the definitions used by DOD. See also DOD
Dictionary, May 2023, p. 68.
380 DOD Dictionary, May 2023, p. 121.
381 Ibid., p. 80. Also note, the DOD Dictionary draws a distinction between “Forward Operating Site” and a “Forward
Operating Base” the latter of which the DOD Dictionary it defines as “an airfield used to support tactical operations
without establishing full support facilities.”
382 Ibid., p. 44.
383 CJCS, Joint Publication 4-04, January 2019, pp. II-2-II-3.
384 As an example, Camp Kosciusko—a U.S. Army forward operating site in Poland—has been described by senior
executive branch officials and multiple DOD sources as a “permanent forward headquarters,” a “permanent garrison,”
etc. See Mark Heeter, “Army Establishes Permanent Garrison in Poland,” U.S. Army, March 21, 2023,
https://www.army.mil/article/265027/army_establishes_permanent_garrison_in_poland. See also Spc. David Klegan,
“Easternmost Army base in Europe now named after Polish-American hero,” Defense Visual Information Distribution
Service, July 30, 2022, https://www.dvidshub.net/news/426178/easternmost-army-base-europe-now-named-after-
polish-american-hero#.
385 The U.S. Southern Command website, for instance, states that cooperative security locations “are not bases… they
are tenant activities on existing airfields whose purpose is to support [U.S.] missions.” U.S. SOUTHCOM,
(continued...)
Congressional Research Service

66

link to page 22 U.S. Overseas Basing: Background and Issues for Congress

be used inconsistently in colloquial or casual descriptions by U.S. or foreign officials and other
stakeholders.
DOD real property accounting methods may further compound uncertainty. To meet its statutory
reporting requirements, every fiscal year (FY) the Department publishes a “Base Structure
Report” (BSR).386 Despite its title, this document does not report real property by base, but rather
by site.387 According to the “Summary” section of the FY2023 BSR (the most recent publicly-
available report), DOD maintains 511 overseas sites.388 However, this figure does not appear to be
a reliable proxy for the number of overseas bases as defined by this report, for two reasons. First,
multiple sites are sometimes reported for a location that DOD’s stated definitions suggest should
constitute a single base.389 Second, there are some active military sites that meet the criteria for
overseas bases, but do not appear on the BSR.390
DOD also maintains a classified “Enduring Location Master List (ELML”) which it uses to
“identify, validate, and document locations that represent an enduring, strategic U.S. security
interest for the foreseeable future.”391 As this document is classified, its contents were not used in
the preparation of this report.
Other shifts in DOD’s approach to overseas basing may also complicate the question of what
constitutes an overseas base. Compared to basing during the Cold War, DOD’s current posture
relies to a larger extent on defense infrastructure owned and operated by allied and partner
nations. Some of these sites are not associated with any locations designated in official DOD or
USG documentation as overseas bases, yet routinely host deployed U.S. forces and/or receive
upgrades to real property funded by the services’ military construction (MILCON)
appropriations.392

https://www.southcom.mil/Media/Special-Coverage/Cooperative-Security-Locations/. Conversely, one general officer
described Naval Base Manda Bay in Kenya as being one component of a broader CSL. DOD, “Department of Defense
Press Briefing on U.S. Africa Command Investigation of Jan. 5, 2020, Al-Shabaab Attack at the Cooperative Security
Location in Manda Bay,” Kenya, March 10, 2022,
https://www.defense.gov/News/Transcripts/Transcript/Article/2963240/department-of-defense-press-briefing-on-us-
africa-command-investigation-of-jan/.
386 10 U.S.C. §2721 requires the Secretary of Defense to maintain records of fixed property and installations. For more
information, refer to the “Relevant Statutory Authorities” section of this report.
387 Recent BSRs define a site as “a specific geographic location that has individual land parcels or facilities assigned to
it.” The FY2023 BSR purports to include all sites that occupy 10 acres or more, and/or have a “plant replacement
value” of $10 million or more. “FY2023 Base Structure Report”, DOD, 2023. Available for download at
https://www.acq.osd.mil/eie/BSI/BEI_Library.html.
388 Despite the listing of 511 overseas sites in its “Summary,” the FY2023 BSR’s “Federal DOD Main Report” section
only provided information for 379 of these. Ibid.
389 The BSRs are published as a tool for tracking DOD real property and infrastructure; these reports account for
different types of sites separately. For example, the FY2023 BSR lists eight separate sites for Aviano Air Base in Italy,
which include one identified simply as “Aviano AB” and others identified variously as housing complexes, storage
facilities and a headquarters building.
390 For example, the FY2023 BSR does not include any sites associated with Saudi Arabia despite the presence of
thousands of U.S. servicemembers in the country.
391 For more information on the ELML, see DOD, DOD Instruction 3000.12 Management of U.S. Global Defense
Posture (GDP), May 8, 2017, p. 11,
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/300012p.pdf#page=11. For reference to
classification, see DOD, DOD Instruction 4165.14 Real Property Inventory and Reporting, September 8, 2023, p. 20,
https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/416514p.pdf#page=20.
392 As an example, Ämari Air Base in Estonia has hosted recurrent U.S. fighter squadron deployments and received
MILCON appropriations for infrastructure improvements, yet CRS was not able to locate its designation in any USG
documentation (e.g., DOD BSRs) as an overseas base.
Congressional Research Service

67

U.S. Overseas Basing: Background and Issues for Congress

A final factor for consideration is the political significance—both domestically and
internationally—of characterizing locations as overseas bases. The executive branch generally,
and DOD specifically, may choose not to apply the term to sites that otherwise meet their criteria
in order to minimize public or congressional scrutiny of politically, diplomatically, or militarily
sensitive executive branch actions.393 They may also avoid the term out of deference to host-
nation sensitivities, or to minimize risks from regional state or non-state actors that might seek to
target U.S. forces.394

Author Information

Luke A. Nicastro
Andrew Tilghman
Analyst in U.S. Defense Infrastructure Policy
Analyst in U.S. Defense Infrastructure Policy

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material.

393 In 1985, for instance, domestic controversy surrounding U.S. military involvement in Central America led the
executive branch to deny that it had established, or sought to establish, “bases or any other permanent facilities in
Honduras,” even though DOD site survey and construction activities in Honduras were documented as early as August
1983. For more information, see Report of the Delegation to Latin America of the Committee on Armed Services House
of Representatives, 99th Cong., 1st sess., April 1985, p. 34; and U.S. Southern Command, 1983 Historical Report, p.
14, https://digital.lib.washington.edu/researchworks/bitstream/handle/1773/45384/17-CV-
01854_19840629__Doc.pdf?sequence=1&isAllowed=y.
394 For example, media reports suggest that a 2024 basing deal with Qatar was not publicly announced due to either
Qatari or U.S. sensitivities. See Alex Marquardt and Natasha Bertrand, “U.S. Quietly Reaches Agreement with Qatar,”
CNN, January 2, 2024, https://www.cnn.com/2024/01/02/politics/us-qatar-agreement-largest-base-middle-
east/index.html.
Congressional Research Service
R48123 · VERSION 1 · NEW
68