U.S. Indo-Pacific Command (INDOPACOM)
March 5, 2024
U.S. Indo-Pacific Command (INDOPACOM)
Overview
Focal Points in the INDOPACOM AOR
U.S. Indo-Pacific Command (USINDOPACOM or
INDOPACOM plans for contingencies throughout the
INDOPACOM) is one of six Department of Defense
AOR. The following hotspots could for various reasons
(DOD) geographic unified combatant commands. The
implicate U.S. national security and military forces.
commander of INDOPACOM exercises authority over
military forces assigned to the command’s area of
Taiwan. The PRC claims sovereignty over self-ruled
responsibility (AOR), which includes the Pacific Ocean and
Taiwan and has long vowed to unify with it, by force if
about half of the Indian Ocean, as well as countries along
necessary. The 1979 Taiwan Relations Act (TRA; P.L. 96-
their coastlines. INDOPACOM is headquartered outside of
8; 22 U.S.C. §3301) states that it is U.S. policy “to maintain
Honolulu, Hawaii, and approximately 375,000 military and
the capacity” to “resist any resort to force or other forms of
civilian personnel are assigned to its AOR. Congress may
coercion that would jeopardize” Taiwan’s security. The
consider whether DOD’s budget, posture, and regional
TRA does not require the United States to use that capacity
strategy supports U.S. national security interests in the
to defend Taiwan, but DOD identifies a potential conflict in
Indo-Pacific. For additional background, see CRS Report
the Taiwan Strait as “the pacing scenario” for which it is
R47589, U.S. Defense Infrastructure in the Indo-Pacific:
preparing. As such, DOD is “modernizing [its] capabilities,
Background and Issues for Congress, and CRS Report
updating U.S. force posture, and developing new
R47643, Guam: Defense Infrastructure and Readiness.
operational concepts,” alongside longstanding U.S. efforts
to bolster Taiwan’s defensive capabilities in accordance
Mission, Posture, and Organization
with the TRA. Among recent actions taken by Congress to
DOD has often referred to the INDOPACOM AOR as the
support Taiwan’s defense are several provisions of the
department’s “priority theater.” The 2022 National Defense
Taiwan Enhanced Resilience Act (Title LV, Subtitle A of
Strategy states “the most comprehensive and serious
the James M. Inhofe National Defense Authorization Act
challenge to U.S. national security is [China]’s coercive and
for Fiscal Year 2023; P.L. 117-263).
increasingly aggressive endeavor to refashion the Indo-
Pacific region and the international system.” DOD has also
Korean Peninsula. The threat from North Korea has
identified regional threats from Russia and North Korea.
served as the raison d’être for the U.S.-South Korea
alliance since 1953, when the two countries signed a
As of September 2023, most of the active-duty U.S.
Mutual Defense Treaty at the end of the Korean War. As
servicemembers assigned to locations in the INDOPACOM
North Korea continues to advance its ballistic missile and
AOR were based in Japan (53,246), Hawaii (44,545), South
nuclear weapons programs, the United States faces a
Korea (24,159), and Guam (6,363). DOD operates or has
number of challenges: enhancing alliance preparedness to
access to over 40 military sites in the region. U.S. forces
respond to North Korean aggression without triggering a
based at these sites comprise ground units (including the
military conflict; reinforcing the credibility of U.S.
Army’s 2nd Infantry Division and the Marine Corps’ III
extended deterrence; and preparing for the eventual transfer
Marine Expeditionary Force), naval warships (including an
of wartime operational control of alliance forces from a
aircraft carrier, destroyers, cruisers, and amphibious assault
U.S. commander to a South Korean commander. Some
ships), and aircraft (including rotary-wing, fighter,
analysts have suggested North Korea may be emboldened
electronic attack, bomber, airlift, and tanker units).
by its improving military capabilities, and its seemingly
close relations with China (and particularly Russia since
INDOPACOM is commanded by a four-star general or flag
Moscow’s 2022 invasion of Ukraine) to engage in military
officer. To date, all commanders have been Navy admirals;
provocations against United States or South Korea.
the current commander is Admiral John Aquilino.
INDOPACOM encompasses five subordinate service
South China Sea. Multiple Asian governments claim
component commands (U.S. Army Pacific, U.S. Pacific
sovereignty over islands and other geographic features in
Fleet, U.S. Marine Forces Pacific, U.S. Pacific Air Forces,
the South China Sea, one of the world’s most heavily
and U.S. Space Forces Pacific) and three subordinate
trafficked waterways. The PRC, which claims most of the
unified commands (U.S. Forces Japan, U.S. Forces Korea,
sea, has conducted land reclamation (island-building),
and Special Operations Command Pacific). INDOPACOM
constructed military facilities on natural and artificial
routinely participates in multinational exercises and other
maritime outposts, and used coercive tactics to impede the
security cooperation activities with regional partners.
activities of other countries, including the Philippines, a
mutual defense treaty ally. Successive U.S. administrations
have accused the PRC of deploying its military vessels and
aircraft in an unsafe and unprofessional manner against
U.S. and other militaries operating in the South China Sea.
https://crsreports.congress.gov
U.S. Indo-Pacific Command (INDOPACOM)
Figure 1. The U.S. INDOPACOM AOR and Selected U.S. Bases
Source: CRS Report R47589, U.S. Defense Infrastructure in the Indo-Pacific: Background and Issues for Congress.
Notes: AFB is Air Force Base; JB is Joint Base; MCAS is Marine Corps Air Station; MCB is Marine Corps Base; NAS is Naval Air Station; and
USAG is U.S. Army Garrison.
East China Sea. The PRC, Japan, and Taiwan all claim
principle of Indo-Pacific posture. As part of this strategic
sovereignty over the Senkaku Islands in the East China Sea.
shift, the U.S. military has increased the number of
Since 2010, PRC-Japan tensions over the dispute have
personnel stationed in the region, secured access to new
simmered as the PRC’s maritime forces have increased
bases (especially in Australia and the Philippines), and
their operations near the islands, which Japan controls. It
developed new operational concepts that emphasize wider
has been U.S. policy since 1972 that the Senkakus are
and more diversified combat and logistical operations (i.e.,
covered under Article 5 of the U.S.-Japan Security Treaty,
the Army’s Multi-Domain Operations, the Air Force’s
which states that the United States commits to “meet the
Agile Combat Employment, the Navy’s Distributed
common danger” of an armed attack on “the territories
Maritime Operations, and the Marine Corps’ Expeditionary
under the Administration of Japan.” Okinawa, which is part
Advanced Basing Operations). Despite this, some argue
of the same island chain, is home to more than half of the
that INDOPACOM is not adequately prepared for the
54,000 U.S. troops based in Japan. Japan has bolstered its
challenges of a great power war. Congress may consider
military presence on the southwestern-most of the
whether or not to change INDOPACOM’s posture—for
Okinawan islands—around 60 nautical miles from
example, by requiring DOD to assign additional forces and
Taiwan—as tensions with China have grown.
capabilities to the region, or directing INDOPACOM to
review the regional infrastructure needs of the services’
Issues for Congress
new operational concepts—to enhance its ability to deter
Resourcing INDOPACOM. Congress may assess whether
and, if necessary, defeat the PRC.
DOD funding requests align with national interests. DOD
requested $9.1 billion for the Pacific Deterrence Initiative
Force Protection. Much of the INDOPACOM AOR is
(PDI) in its FY2024 budget. PDI does not cover the totality
within range of the PRC’s conventional ballistic and cruise
of departmental resources required to sustain
missile arsenal (some locations are vulnerable to North
INDOPACOM operations and the pursuit of regional
Korean and Russian missiles as well). As a result, U.S.
strategic objectives. Congress may, therefore, assess the
bases, personnel, and weapons systems may be at risk of
strategic alignment of INDOPACOM funding more
attack in the event of a regional conflict. Congress may
holistically, to include basing, personnel, and equipment
assess the degree to which INDOPACOM’s existing air and
needs alongside common services and support provided by
missile defense architecture affords protection from these
defense agencies and field activities.
threats, and consider whether or not to make additional
appropriations, enact legislation, or conduct oversight
Posturing INDOPACOM for Great Power Competition.
activities aimed at strengthening these capabilities.
Since the early 2010s, DOD has increasingly come to
identify competition with the PRC as the organizing
Caitlin Campbell, Analyst in Asian Affairs
https://crsreports.congress.gov
U.S. Indo-Pacific Command (INDOPACOM)
Luke A. Nicastro, Analyst in U.S. Defense Infrastructure
Cameron M. Keys, Analyst in Defense Logistics and
Policy
Resource Management Policy
IF12604
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