U.S. Strategic Nuclear Forces: Background,
Developments, and Issues
Amy F. Woolf
Specialist in Nuclear Weapons Policy
May 3, 2010
Congressional Research Service
7-5700
www.crs.gov
RL33640
CRS Report for Congress
P
repared for Members and Committees of Congress
U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Summary
During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for
nuclear weapons. The longer range systems, which included long-range missiles based on U.S.
territory, long-range missiles based on submarines, and heavy bombers that could threaten Soviet
targets from their bases in the United States, are known as strategic nuclear delivery vehicles. At
the end of the Cold War, in 1991, the United States deployed more than 10,000 warheads on these
delivery vehicles. That number has declined to less than 6,000 warheads today, and is slated,
under the 2002 Moscow Treaty, to decline to 2,200 warheads by the year 2012. The United States
and Russia recently completed a new START treaty that will further reduce U.S. forces to
between 1,550 deployed warheads.
At the present time, the U.S. land-based ballistic missile force (ICBMs) consists of 450
Minuteman III ICBMs, each deployed with between one and three warheads, although they will
all be reduced to only one warhead over the next few years. The Air Force has deactivated all 50
of the 10-warhead Peacekeeper ICBMs; it plans to deploy Peacekeeper warheads on some of the
Minuteman ICBMs. It has also deactivated 50 Minuteman III missiles. The Air Force is also
modernizing the Minuteman missiles, replacing and upgrading their rocket motors, guidance
systems, and other components. The Air Force had expected to begin replacing the Minuteman
missiles around 2018, but has decided, instead, to continue to modernize and maintain the
existing missiles, so that they can remain in the force through 2030.
The U.S. ballistic missile submarine fleet currently consists of 14 Trident submarines; each
carries 24 Trident II (D-5) missiles. The Navy has converted 4 of the original 18 Trident
submarines to carry non-nuclear cruise missiles. The remaining submarines currently carry
around 1,200 warheads in total, a number that has been declining decline as the United States
implements the Moscow Treaty. The Navy has shifted the basing of the submarines, so that nine
are deployed in the Pacific Ocean and five are in the Atlantic, to better cover targets in and around
Asia. It also has undertaken efforts to extend the life of the missiles and warheads so that they and
the submarines can remain in the fleet past 2020, and to begin design work on a new submarine.
The U.S. fleet of heavy bombers currently includes 19 B-2 bombers and 94 B-52 bombers. The
B-1 bomber no longer is equipped for nuclear missions. The 2006 QDR recommended that the
Air Force reduce the B-52 fleet to 56 aircraft; Congress rejected that recommendation, but will
allow the fleet to decline to 76 aircraft. The Air Force has also begun to retire the nuclear-armed
cruise missiles carried by B-52 bombers, leaving only about half the B-52 fleet equipped to carry
nuclear weapons.
The Obama Administration recently completed a review of the size and structure of the U.S.
nuclear force as a part of the congressionally mandated Nuclear Posture Review. It has also
recently signed a New START Treaty with Russia that will limit the number of deployed missiles
and warheads in the U.S. strategic force. Congress will review the Administration’s plans for U.S.
strategic nuclear forces during the annual authorization and appropriations process, and if it
assesses the terms of a prospective nuclear arms control treaty with Russia.
This report will be updated as needed.
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U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Contents
Introduction ................................................................................................................................ 1
Background: The Strategic Triad ................................................................................................. 2
Force Structure and Size During the Cold War....................................................................... 2
Force Structure and Size After the Cold War.......................................................................... 4
Current and Future Force Structure and Size.......................................................................... 6
Strategic Nuclear Delivery Vehicles: Current Plans and Modernization Programs ........................ 8
Intercontinental Ballistic Missiles (ICBMs)........................................................................... 8
Peacekeeper (MX) .......................................................................................................... 8
Minuteman III................................................................................................................. 9
Minuteman Modernization Programs ............................................................................ 12
Future Programs............................................................................................................ 14
Submarine Launched Ballistic Missiles ............................................................................... 14
The SSGN Program ...................................................................................................... 15
The Backfit Program..................................................................................................... 15
Basing Changes ............................................................................................................ 16
Warhead Issues ............................................................................................................. 17
Modernization Plans and Programs ............................................................................... 17
Future Programs............................................................................................................ 19
Bombers ............................................................................................................................. 20
B-1 Bomber .................................................................................................................. 20
B-2 Bomber .................................................................................................................. 20
B-52 Bomber ................................................................................................................ 21
Future Bomber Plans..................................................................................................... 25
Issues for Congress ................................................................................................................... 26
Force Size ........................................................................................................................... 26
Force Structure.................................................................................................................... 28
Safety, Security, and Management Issues............................................................................. 29
Figures
Figure 1. U.S. Strategic Nuclear Weapons: 1960-1990................................................................. 3
Figure 2. U.S. Strategic Nuclear Forces: 1990-2009 .................................................................... 5
Tables
Table 1. U.S. Strategic Nuclear Forces Under START I and START II......................................... 6
Table 2. U.S. Strategic Nuclear Forces under New START .......................................................... 8
Contacts
Author Contact Information ...................................................................................................... 30
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U.S. Strategic Nuclear Forces: Background, Developments, and Issues
Introduction
During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for
nuclear weapons, including short-range missiles and artillery for use on the battlefield, medium-
range missiles and aircraft that could strike targets beyond the theater of battle, short- and
medium-range systems based on surface ships, long-range missiles based on U.S. territory and
submarines, and heavy bombers that could threaten Soviet targets from their bases in the United
States. The short- and medium-range systems are considered non-strategic nuclear weapons and
have been referred to as battlefield, tactical, and theater nuclear weapons.1 The long-range
missiles and heavy bombers are known as strategic nuclear delivery vehicles.
In 1990, as the Cold War was drawing to a close and the Soviet Union was entering its final year,
the United States had more than 12,000 nuclear warheads deployed on 1,875 strategic nuclear
delivery vehicles.2 As of July 1, 2009, according to the counting rules in the Strategic Arms
Reduction Treaty (START), the United States had reduced to 5,916 nuclear warheads on 1,188
strategic nuclear delivery vehicles.3 According to the State Department, the United States had
reduced its number of operationally deployed warheads, a number that excludes many warheads
that count under START, to 2,246 by the end of December 31, 2008.4 Under the terms of the 2002
Strategic Offensive Reduction Treaty (known as the Moscow Treaty) between the United States
and Russia, this number was to decline to no more than 2,200 operationally deployed strategic
nuclear warheads by the end of 2012. The State Department has reported that the United States
has already reached that level, with only 1,968 operationally deployed strategic warheads in
December 2009.5 The New START Treaty, signed by President Obama and President Medvedev
on April 8, 2010, reduces those forces further, to no more than 1,550 warheads on deployed
launchers and heavy bombers.6
Although these numbers do not count the same categories of nuclear weapons, they indicate that
the number of deployed warheads on U.S. strategic nuclear forces has declined significantly in
the two decades following the end of the Cold War. Yet, nuclear weapons continue to play a key
role in U.S. national security strategy, and the United States does not, at this time, plan to either
eliminate its nuclear weapons or abandon the strategy of nuclear deterrence that has served as a
core concept in U.S. national security strategy for more than 60 years. In a speech in Prague on
April 5, 2009, President Obama highlighted “America’s commitment to seek the peace and
1 For a detailed review of U.S. nonstrategic nuclear weapons see, CRS Report RL32572, Nonstrategic Nuclear
Weapons, by Amy F. Woolf.
2 Natural Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data.
http://www.nrdc.org/nuclear/nudb/datab1.asp The same source indicates that the Soviet Union, in 1990, had just over
11,000 warheads on 2,332 strategic nuclear delivery vehicles.
3 Russia, by the same accounting, had 3,909 warheads on 814 delivery vehicles. See U.S. Department of State, Bureau
of Verification, Compliance and Inspection. Fact Sheet. START Aggregate Numbers of Strategic Offensive Weapons.
October 1, 2009. Washington, DC.
4 The State Department did not provide an unclassified estimate for Russia’s current force of operationally deployed
warheads. See, U.S. Department of State, Bureau of Verification, Compliance, and Inspection. 2009 Annual Report on
Implementation of the Moscow Treaty. p. 2.
5 U.S. State Department, Bureau of Public Affairs, The Nuclear Nonproliferation Treaty: Promoting Disarmament,
Washington, D.C., April 27, 2010, http://www.state.gov/documents/organization/141497.pdf.
6 For more information on the New START Treaty, see CRS Report R41219, The New START Treaty: Central Limits
and Key Provisions, by Amy F. Woolf.
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U.S. Strategic Nuclear Forces: Background, Developments, and Issues
security of a world without nuclear weapons.” But he recognized that this goal would not be
reached quickly, and probably not in his lifetime.7 And, even though the President pledged to
reduce the roles and numbers of U.S. nuclear forces, the 2010 Nuclear Posture Review noted that
“the fundamental role of U.S. nuclear weapons, which will continue as long as nuclear weapons
exist, is to deter nuclear attack on the United States, our allies, and partners.”8
The Bush Administration, after completing the 2002 Nuclear Posture Review (NPR) indicated
that the United States would reduce its forces to 2,200 operationally deployed warheads, the
number and concept codified in the Moscow Treaty, but it did not identify the specific
combination of delivery vehicles or warhead loadings that the United States would maintain to
reach the specified number. Subsequent Pentagon studies, including the Strategic Capabilities
Assessment in 2005 and the 2006 Quadrennial Defense Review (QDR), offered further guidance
on strategic nuclear force structure.
The Obama Administration, in the 2010 Nuclear Posture Review, indicated that the United States
would reduce its forces further, to 1,550 warheads, as mandated by the New START Treaty
signed on April 8, 2010. The Obama Administration has not yet specified which forces it will
deploy within these limits. However, in the NPR and in the documents released with the FY2011
budget, the Administration indicated that the United States is planning to pursue programs that
will allow it to modernize and adjust its strategic forces so that they remain capable in the years
that follow.
This report reviews the ongoing programs that will affect the expected size and shape of the U.S.
strategic nuclear force structure. It begins with an overview of this force structure during the Cold
War, and summarizes the reductions and changes that have occurred since 1991. It then offers
details about each category of delivery vehicle—land-based intercontinental ballistic missiles
(ICBMs), submarine launched ballistic missiles (SLBMs) and heavy bombers—focusing on their
current deployments and ongoing and planned modernization programs. The report concludes
with a discussion of issues related to decisions about the future size and shape of the U.S.
strategic nuclear force.
Background: The Strategic Triad
Force Structure and Size During the Cold War
Since the early 1960s the United States has maintained a “triad” of strategic nuclear delivery
vehicles. The United States first developed these three types of nuclear delivery vehicles, in large
part, because each of the military services wanted to play a role in the U.S. nuclear arsenal.
However, during the 1960s and 1970s, analysts developed a more reasoned rationale for the
nuclear “triad.” They argued that these different basing modes had complementary strengths and
weaknesses. They would enhance deterrence and discourage a Soviet first strike because they
complicated Soviet attack planning and ensured the survivability of a significant portion of the
7 The White House, Office of the Press Secretary, Remarks by President Obama, Prague, Czech Republic, April 5,
2009, http://www.whitehouse.gov/the_press_office/Remarks-By-President-Barack-Obama-In-Prague-As-Delivered/.
8 U.S. Department of Defense, Nuclear Posture Review, Washington, D.C., April 6, 2010, p. 15.
http://www.defense.gov/npr/docs/2010%20Nuclear%20Posture%20Review%20Report.pdf
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U.S. force in the event of a Soviet first strike.9 The different characteristics might also strengthen
the credibility of U.S. targeting strategy. For example, ICBMs eventually had the accuracy and
prompt responsiveness needed to attack hardened targets such as Soviet command posts and
ICBM silos, SLBMs had the survivability needed to complicate Soviet efforts to launch a
disarming first strike and to retaliate if such an attack were attempted,10 and heavy bombers could
be dispersed quickly and launched to enhance their survivability, and they could be recalled to
their bases if a crisis did not escalate into conflict.
According to unclassified estimates, the number of delivery vehicles (ICBMs, SLBMs, and
nuclear-capable bombers) in the U.S. force structure grew steadily through the mid-1960s, with
the greatest number of delivery vehicles, 2,268, deployed in 1967.11 The number then held
relatively steady through 1990, at between 1,875 and 2,200 ICBMs, SLBMs, and heavy bombers.
The number of warheads carried on these delivery vehicles increased sharply through 1975, then,
after a brief pause, again rose sharply in the early 1980s, peaking at around 13,600 warheads in
1987. Figure 1 displays the increases in delivery vehicles and warheads between 1960, when the
United States first began to deploy ICBMs, and 1990, the year before the United States and
Soviet Union signed the Strategic Arms Reduction Treaty (START).
Figure 1. U.S. Strategic Nuclear Weapons: 1960-1990
16000
14000
12000
10000
er
8000
mb
Nu
6000
4000
2000
0
60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90
Year
Launchers
Warheads
Source: Natural Resources Defense Council, Archive of Nuclear Data.
The sharp increase in warheads in the early 1970s reflects the deployment of ICBMs and SLBMs
with multiple warheads, known as MIRVs (multiple independent reentry vehicles). In particular,
the United States began to deploy the Minuteman III ICBM, with 3 warheads on each missile, in
9 U.S. Department of Defense. Annual Report to Congress, Fiscal Year 1989, by Frank Carlucci, Secretary of Defense.
February 18, 1988. Washington, 1988. p. 54.
10 In the early 1990s, SLBMs also acquired the accuracy needed to attack many hardened sites in the former Soviet
Union.
11 Natural Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data.
http://www.nrdc.org/nuclear/nudb/datab1.asp
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1970, and the Poseidon SLBM, which could carry 10 warheads on each missile, in 1971.12 The
increase in warheads in the mid-1980s reflects the deployment of the Peacekeeper (MX) ICBM,
which carried 10 warheads on each missile.
In 1990, before it concluded the START Treaty, the United States deployed a total of around
12,304 warheads on its ICBMs, SLBMs, and heavy bombers. The ICBM force consisted of
single-warhead Minuteman II missiles, 3-warhead Minuteman III missiles, and 10-warhead
Peacekeeper (MX) missiles, for a total force of 2,450 warheads on 1,000 missiles. The submarine
force included Poseidon submarines with Poseidon C-3 and Trident I (C-4) missiles, and the
newer Trident submarines with Trident I, and some Trident II (D-5) missiles. The total force
consisted of 5,216 warheads on around 600 missiles.13 The bomber force centered on 94 B-52H
bombers and 96 B-1 bombers, along with many of the older B-52G bombers and 2 of the new (at
the time) B-2 bombers. This force of 260 bombers could carry over 4,648 weapons.
Force Structure and Size After the Cold War
During the 1990s, the United States reduced the numbers and types of weapons in its strategic
nuclear arsenal, both as a part of its modernization process and in response to the limits in the
1991 START Treaty. The United States continued to maintain a triad of strategic nuclear forces,
however, with warheads deployed on ICBMs, SLBMs, and bombers. According to the
Department of Defense, this mix of forces not only offered the United States a range of
capabilities and flexibility in nuclear planning and complicated an adversary’s attack planning,
but also hedged against unexpected problems in any single delivery system. This latter issue
became more of a concern in this time period, as the United States retired many of the different
types of warheads and missiles that it had deployed over the years, reducing the redundancy in its
force.
The 1991 START Treaty limited the United States to a maximum of 6,000 total warheads, and
4,900 warheads on ballistic missiles, deployed on up to 1,600 strategic offensive delivery
vehicles. However, the Treaty did not count the actual number of warheads deployed on each type
of ballistic missile or bomber. Instead, it used “counting rules” to determine how many warheads
would count against the Treaty’s limits. For ICBMs and SLBMs, this number usually equaled the
actual number of warheads deployed on the missile. Bombers, however, used a different system.
Bombers that were not equipped to carry air-launched cruise missiles (the B-1 and B-2 bombers)
counted as one warhead; bombers equipped to carry air-launched cruise missiles (B-52 bombers)
could carry 20 missiles, but would only count as 10 warheads against the Treaty limits. These
rules have led to differing estimates of the numbers of warheads on U.S. strategic nuclear forces
during the 1990s; some estimates count only those warheads that count against the Treaty while
others count all the warheads that could be carried by the deployed delivery systems.
12 GlobalSecurity.org LGM Minuteman III History and Poseidon C-3 History. http://www.globalsecurity.org/wmd/
systems/lgm-30_3-hist.htm and http://www.globalsecurity.org/wmd/systems/c-3.htm
13 The older Poseidon submarines were in the process of being retired, and the number of missiles and warheads in the
submarine fleet dropped quickly in the early 1990s, to around 2,688 warheads on 336 missiles by 1993. See Natural
Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data.
http://www.nrdc.org/nuclear/nudb/datab1.asp
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Figure 2. U.S. Strategic Nuclear Forces: 1990-2009
10000
9000
8000
7000
r
e
6000
b
5000
4000
Num
3000
2000
1000
0
91
93
95
97
99
3
7
2001
200
2005
200
2009
Year
Launchers
Warheads
Source: Natural Resources Defense Council, Archive of Nuclear Data.
According to the data from the Natural Resources Defense Council, the United States reduced its
nuclear weapons from 9,300 warheads on 1,239 delivery vehicles in 1991 to 6,196 warheads on
1,064 delivery vehicles when it completed the implementation of START in 2001. By 2009, the
United States had reduced its forces to approximately 2,200 warheads on around 850 delivery
vehicles. According to the State Department, as of December 2009, the United States had 1,968
operationally deployed warheads on its strategic offensive nuclear forces.14 These numbers appear in
Figure 2.
During the 1990s, the United States continued to add to its Trident fleet, reaching a total of 18
submarines. It retired all of its remaining Poseidon submarines and all of the single-warhead
Minuteman II missiles. It continued to deploy B-2 bombers, reaching a total of 21, and removed
some of the older B-52G bombers from the nuclear fleet. Consequently, in 2001, its warheads were
deployed on 18 Trident submarines with 24 missiles on each submarine and 6 or 8 warheads on each
missile; 500 Minuteman III ICBMs, with one or 3 warheads on each missile; 50 Peacekeeper (MX)
missiles, with 10 warheads on each missile; 94 B-52H bombers, with up to 20 cruise missiles on
each bomber; and 21 B-2 bombers with up to 16 bombs on each aircraft.
The United States and Russia signed a second START Treaty in early 1993. Under this Treaty, the
United States would have had to reduce its strategic offensive nuclear weapons to between 3,000
and 3,500 accountable warheads. In 1994, the Department of Defense decided that, to meet this
limit, it would deploy a force of 500 Minuteman III ICBMs with one warhead on each missile, 14
Trident submarines with 24 missiles on each submarine and 5 warheads on each missile, 76 B-52
bombers, and 21 B-2 bombers. The Air Force was to eliminate 50 Peacekeeper ICBMs and
reorient the B-1 bombers to non-nuclear missions; the Navy would retire 4 Trident submarines (it
later decided to convert these submarines to carry conventional weapons). This Treaty never
entered into force and Congress prevented the Clinton Administration from reducing U.S. forces
14 U.S. Department of State, Bureau of Verification, Compliance, and Implementation, The Legacy of START and
Related U.S. Policies, Fact Sheet, Washington, D.C., July 16, 2009, http://www.state.gov/t/vci/rls/126119.htm.
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unilaterally to START II limits. Nevertheless, the Navy and Air Force continued to plan for the
forces described above, and eventually implemented those changes. Table 1 displays the forces
the United States had deployed in 2001, after completing the START I reductions. It also includes
those that it would have deployed under START II, in accordance the with 1994 decisions.
Table 1. U.S. Strategic Nuclear Forces Under START I and START II
Deployed under START I (2001)
Planned for START II
Accountable
Accountable
System
Launchers
Warheadsa Launchers Warheads
Minuteman III ICBMs
500
1,200
500
500
Peacekeeper ICBMs
50
500
0
0
Trident I Missiles
168
1,008
0
0
Trident
II
Missiles
264 2,112
336 1,680
B-52 H Bombers (ALCM)
97
970
76
940
B-52 H Bombers (non-
ALCM)
47 47
0 0
B-1 Bombersb 90
90
0
0
B-2 Bombers
20
20
21
336
Total
1,237 5,948
933 3,456
a. Under START I, bombers that are not equipped to carry ALCMs count as one warhead, even if they can
carry up 16 nuclear bombs; bombers that are equipped to carry ALCMs count as 10 warheads, even if they
can carry up to 20 ALCMs.
b. Although they still count under START I, B-1 bombers are no longer equipped for nuclear missions.
Current and Future Force Structure and Size
The Bush Administration stated in late 2001 that the United States would reduce its strategic
nuclear forces to 1,700-2,200 “operationally deployed warheads” over the next decade.15 This
goal was codified in the 2002 Moscow Treaty. According to the Bush Administration,
operationally deployed warheads were those deployed on missiles and stored near bombers on a
day-to-day basis. They are the warheads that would be available immediately, or in a matter of
days, to meet “immediate and unexpected contingencies.”16 The Administration also indicated
that the United States would retain a triad of ICBMs, SLBMs, and heavy bombers for the
foreseeable future. It did not, however, offer a rationale for this traditional “triad,” although the
points raised in the past about the differing and complementary capabilities of the systems
probably still pertain. Admiral James Ellis, the former Commander of the U.S. Strategic
Command (STRATCOM) highlighted this when he noted in a 2005 interview, that the ICBM
15 President Bush announced the U.S. intention to reduce its forces on November 13, 2001, during a summit with
Russia’s President Vladimir Putin. The United States and Russia codified these reductions in a Treaty signed in May
2002. See CRS Report RL31448, Nuclear Arms Control: The Strategic Offensive Reductions Treaty, by Amy F. Woolf.
16 U.S. Senate. Committee on Armed Services. Statement of the Honorable Douglas J. Feith, Undersecretary of Defense
For Policy. February 14, 2002.
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force provides responsiveness, the SLBM force provides survivability, and bombers provide
flexibility and recall capability.17
The Bush Administration did not specify how it would reduce the U.S. arsenal from around 6,000
warheads to the lower level of 2,200 operationally deployed warheads, although it did identify
some force structure changes that would account for part of the reductions. Specifically, after
Congress removed its restrictions,18 the United States eliminated the 50 Peacekeeper ICBMs,
reducing by 500 the total number of operationally deployed ICBM warheads. It also continued
with plans to remove 4 Trident submarines from service, and converted those ships to carry non-
nuclear guided missiles. These submarines would have counted as 476 warheads under the
START Treaty’s rules. These changes reduced U.S. forces to around 5,000 warheads on 950
delivery vehicles in 2006; this reduction appears in Figure 2. The Bush Administration also noted
that two of the Trident submarines remaining in the fleet would be in overhaul at any given time.
The warheads that could be carried on those submarines would not count against the Moscow
Treaty limits because they would not be “operationally deployed.” This would further reduce the
U.S. deployed force by 200-400 warheads.
The Bush Administration, through the 2005 Strategic Capabilities Assessment and 2006
Quadrennial Defense Review, announced additional changes in U.S. ICBMs, SLBMs, and
bomber forces; these included the elimination of 50 Minuteman III missiles and several hundred
air-launched cruise missiles. (These are discussed in more detail below.) These changes appear to
be sufficient to reduce the number of operationally deployed warheads enough to meet the Treaty
limit of 2,200 warheads, as the United States announced, in mid-2009, that it has met this limit.
Reaching this level, however, also depends on the number of warheads are carried by each of the
remaining Trident and Minuteman.19
The Obama Administration has indicated, in the 2010 NPR, that the United States will retain a
triad of ICBMs, SLBMs, and heavy bombers as the United States reduces its forces to the limits
in the New START Treaty. The NPR indicated that the unique characteristics of each leg of the
triad were important to the goal of maintaining strategic stability at reduced numbers of
warheads:
Each leg of the Triad has advantages that warrant retaining all three legs at this stage of
reductions. Strategic nuclear submarines (SSBNs) and the SLBMs they carry represent the
most survivable leg of the U.S. nuclear Triad…. Single-warhead ICBMs contribute to
stability, and like SLBMs are not vulnerable to air defenses. Unlike ICBMs and SLBMs,
bombers can be visibly deployed forward, as a signal in crisis to strengthen deterrence of
potential adversaries and assurance of allies and partners.20
17 Hebert, Adam. The Future Missile Force. Air Force Magazine. October 2005.
18 Beginning in FY1996, and continuing through the end of the Clinton Administration, Congress had prohibited the
use of any DOD funds for the elimination of strategic nuclear delivery vehicles, below START I levels, until START II
entered into force. See, for example, the FY1998 Defense Authorization Act (P.L. 105-85, Sec. 1302). Congress lifted
this restriction in the FY2002 Defense Authorization Act (P.L. 107-107, Sec. 1031).
19 “U.S. Meets Moscow Nuclear Reduction Commitment Three Years Early,” Global Security Newswire, February 11,
2009.
20 U.S. Department of Defense, Nuclear Posture Review, Washington, D.C., April 6, 2010, p. 22.
http://www.defense.gov/npr/docs/2010%20Nuclear%20Posture%20Review%20Report.pdf
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Moreover, the NPR noted that “retaining sufficient force structure in each leg to allow the ability
to hedge effectively by shifting weight from one Triad leg to another if necessary due to
unexpected technological problems or operational vulnerabilities.”21
Table 2 identifies two potential force structures that the United States might deploy under the
New START Treaty, and compares them with estimates of U.S. operational strategic nuclear
forces in 2010. This structure is consistent with the statements and adjustments the
Administration has made about deploying all Minuteman III missiles with a single warhead,
retaining Trident submarines deployed in two oceans, and converting some number of heavy
bombers to conventional-only missions.
Table 2. U.S. Strategic Nuclear Forces under New START
Estimated Current Forces and Potential New START Forces
Potential Forces Under New START
Estimated Forces 2010
Alternative 1a
Alternative 2b
Total
Deployed
Total
Deployed
Launchers
Warheads
Launchers Launchers Warheads Launchers Launchers Warheads
Minuteman
III
450 500 400 350 350 450 400 400
Trident
336 1152 336 288 1138 288 240 1090
B-52
76 300 44 44 44 44 42 42
B-2
18 200 18 18 18 18 18 18
Total
880 2152 798 700 1550 800 700 1550
Source: CRS estimates.
a. This force assumes that the United States retains 14 Trident submarines, with 2 in overhaul and 24
deployed launchers on each of the 12 remaining submarines.
b. This force assumes that the United States retains 12 Trident submarines, with no submarines in overhaul,
each has only 20 deployed launchers. A further variation would include 14 Trident submarines with 2 in
overhaul, for a total of 336 launchers, but only 20 launchers on each of the deployed submarines. In this
case the United States could retain 400 total Minuteman III ICBMs.
Strategic Nuclear Delivery Vehicles: Current Plans
and Modernization Programs
Intercontinental Ballistic Missiles (ICBMs)
Peacekeeper (MX)
In the late 1980s, the United States deployed 50 Peacekeeper ICBMs, each with 10 warheads, at
silos that had held Minuteman missiles at F.E. Warren Air Force Base in Wyoming. The 1993
21 Ibid. p. 20.
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START II Treaty would have banned multiple warhead ICBMs, so the United States would have
had to eliminate these missiles while implementing the Treaty. Therefore, the Pentagon began
planning for their elimination, and the Air Force added funds to its budget for this purpose in
1994. However, beginning in FY1998, Congress prohibited the Clinton Administration from
spending any money on the deactivation or retirement of these missiles until START II entered
into force. The Bush Administration requested $14 million in FY2002 to begin the missiles’
retirement; Congress lifted the restriction and authorized the funding. The Air Force began to
deactivate the missiles in October 2002, and completed the process, having removed all the
missiles from their silos, in September 2005. The MK21 reentry vehicles and W87 warheads from
these missiles have been placed in storage. As is noted below, the Air Force plans to redeploy
some of these warheads and reentry vehicles on Minuteman III missiles, under the Safety
Enhanced Reentry Vehicle (SERV) program.
Under the terms of START, the United States would have had to eliminate the Peacekeeper
missile silos to remove the warheads on the missiles from accountability under the Treaty limits.
However, the Air Force has chosen to retain the silos. Therefore, the warheads that were deployed
on the Peacekeeper missiles still counted under START, even though the missiles were no longer
operational, until START expired in December 2009. The United States does not, however, count
any of these warheads under the limits in the Moscow Treaty. They also will not count under the
limits in the New START Treaty, if the United States eliminates the silos. It will not, however,
have to blow up or excavate the silos, as it would have had to do under the original START
Treaty. The new START Treaty indicates that the parties can use whatever method they choose to
eliminate the silos, as long as they demonstrate that the silos can no longer launch missiles.
Minuteman III
The U.S. force of Minuteman III ICBMs has declined recently from 500 to 450 missiles. These
missile are located at three Air Force bases—F.E. Warren AFB in Wyoming, Malmstrom AFB in
Montana, and Minot AFB in North Dakota. Each base houses 150 missiles.
Missile Plans
In the 2006 Quadrennial Defense Review (QDR), the Pentagon indicated that it planned to
“reduce the number of deployed Minuteman III ballistic missiles from 500 to 450, beginning in
Fiscal Year 2007.”22 The QDR did not indicate which base was likely to lose a squadron of
missiles, although, in testimony before the Senate Armed Services Committee, General James E.
Cartwright, the Commander of U.S. Strategic Command (STRATCOM), indicated that the
missiles would likely come from Malmstrom because that would leave each base with an equal
number of 150 ICBMs.23 The Air Force deactivated the missiles in Malmstrom’s 564th Missile
Squadron, which was known as the “odd squad.”24 This designation reflected that these missiles
were built and installed by General Electric, while all other Minuteman missiles were built by
Boeing, and that these missiles used a different communications and launch control system than
all the other Minuteman missiles. According to Air Force Space Command, the drawdown began
22 U.S. Department of Defense. Report of the 2006 Quadrennial Defense Review. Washington, February 2006. p. 50.
23 U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James E.
Cartwright, Commander U.S. Strategic Command. March 29, 2006.
24 Johnson, Peter. Growth Worries Base Boosters. Great Falls Tribune. January 19, 2006.
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on July 1, 2007. All of the reentry vehicles were removed from the missiles in early 2008, the
missiles were all removed from their silos by the end of July 2008, and the squadron was
deactivated by the end of August 2008.25
In testimony before the Senate Armed Services Committee, General Cartwright stated that the Air
Force had decided to retire these missiles so that they could serve as test assets for the remaining
force. He noted that the Air Force had to “keep a robust test program all the way through the life
of the program.”26 With the test assets available before this decision, the test program would
begin to run short around 2017 or 2018. The added test assets would support the program through
2025 or longer. This time line, however, raises questions about why the Air Force pressed to
begin retiring the missiles in FY2007, 10 years before it runs out of test assets. Some have
speculated that the elimination of the 50 missiles was intended to reduce the long term operations
and maintenance costs for the fleet, particularly since the 564th Squadron used different ground
control technologies and training systems than the remainder of the fleet. This option was not
likely, however, to produce budgetary savings in the near-term as the added cost of deactivating
the missiles could exceed the reductions in operations and maintenance expenses.27 In addition, to
use these missiles as test assets, the Air Force will include them in the modernization programs
described below. This would further limit the budgetary savings. At the same time, the Air Force
plans to retain the silos at Malmstrom, and will not destroy or eliminate them.
Retiring these missiles might also allow the Air Force to reduce the number of officers needed to
operate the Minuteman fleet and to transfer these officers to different positions, although, again,
the numbers are likely to be small. Nevertheless, by retiring these missiles, both STRATCOM and
the Air Force can participate in the ongoing effort to transform the Pentagon in response to post-
Cold War threats. These missiles may still have a role to play in U.S. national security strategy,
but they may not be needed in the numbers that were required when the United States faced the
Soviet threat.
Congress questioned the Administration’s rationale for this plan to retire 50 Minuteman missiles.
In the FY2007 Defense Authorization Act (H.R. 5122, Sec. 139), Congress stated that DOD could
not spend any money to begin the withdrawal of these missiles from the active force until the
Secretary of Defense submitted a report that addressed a number of issues, including (1) a
detailed justification for the proposal to reduce the force from 500 to 450 missiles; (2) a detailed
analysis of the strategic ramifications of continuing to equip a portion of the force with multiple
independent warheads rather than single warheads; (3) an assessment of the test assets and spares
required to maintain a force of 500 missiles and a force of 450 missiles through 2030; (4) an
assessment of whether halting upgrades to the missiles withdrawn from the deployed force would
compromise their ability to serve as test assets; and (5) a description of the plan for extending the
life of the Minuteman III missile force beyond FY2030. The Secretary of Defense submitted this
report to Congress in late March 2007.
The Obama Administration has not yet indicated how many Minuteman III ICBMs it will retain
under the New START Treaty. However, even if it reduces the number of deployed ICBMs, it can
retain many, if not all of the Minuteman III silos. The Treaty limits the United States and Russia
25 Global Security Newswire. U.S. Deactivates 50 Strategic Missiles. August 4, 2008.
26 U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James E.
Cartwright, Commander U.S. Strategic Command. March 29, 2006.
27 Private communication.
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to 700 deployed ICBMs, deployed SLBMs, and heavy bombers, but contains a higher limit of
800 deployed and nondeployed ICBM launchers, SLBM launchers, and heavy bombers.
Moreover, as was noted above, under the New START Treaty, the United States can eliminate its
ICBM silos without physically destroying them.
Warhead Plans
Each Minuteman III was initially deployed with 3 warheads, for a total of 1,500 warheads across
the force. In 2001, to meet the START limit of 6,000 warheads, the United States removed 2
warheads from each of the 150 Minuteman missiles at F.E. Warren AFB,28 reducing the
Minuteman III force to 1,200 total warheads. In the process, the Air Force also removed and
destroyed the “bulkhead,” the platform on the reentry vehicle, so that, in accordance with START
rules, these missiles can no longer carry 3 warheads.
Under START II, the United States would have had to download all the Minuteman III missiles to
one warhead each. Although the Bush Administration initially endorsed the plan to download all
Minuteman ICBMs, this plan apparently changed. In an interview with Air Force Magazine in
October 2003, General Robert Smolen indicated that the Air Force would maintain the ability to
deploy these 500 missiles with up to 800 warheads.29 Although some analysts interpreted this
statement to mean that the Minuteman ICBMs would carry 800 warheads on a day-to-day basis, it
seems more likely that this was a reference to the Air Force intent to maintain the ability to reload
warheads, and reconstitute the force, if circumstances changed.30 The 2001 NPR had indicated
that the United States would maintain the flexibility to do this. However, in testimony before the
Senate Armed Services Committee, General Cartwright also indicated that some Minuteman
missiles might carry more than one warhead. Specifically, when discussing the reduction from
500 to 450 missiles, he said, “this is not a reduction in the number of warheads deployed. They
will just merely be re-distributed on the missiles.”31 Major General Deppe confirmed that the Air
Force would retain some Minuteman III missiles with more than one warhead when he noted, in a
speech in mid-April 2007, that the remaining 450 Minuteman III missiles could be deployed with
one, two, or three warheads.32
In the 2010 NPR, the Obama Administration has indicated that, under the New START Treaty, all
of the U.S. Minuteman III missiles will carry only one warhead. It indicated that this
configuration would “enhance the stability of the nuclear balance by reducing incentives for
either side to strike first.”33 However, unlike under START, the United States will not have to alter
the front end of the missile or remove the old bulkhead. As a result, the United States could
restore warheads to its ICBM force if the international security environment changed.
28 See Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
29 Hebert, Adam. The Future Missile Force. Air Force Magazine. October 2005.
30 See, for example, Jeffrey Lewis. STRATCOM Hearts MIRV. ArmsControlWonk.com, January 30, 2006.
31 See, U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James
E. Cartwright, Commander U.S. Strategic Command. March 29, 2006.
32 Sirak, Michael. Air Force Prepared To Draaw Down Minuteman III Fleet by 50 Missiles. Defense Daily. April 17,
2007.
33 Single-warhead ICBMs are considered to be stabilizing because it would take two attacking warheads to destroy the
silo. If each side has approximately the same number of warheads, than an attack on a single warhead missile would
cost more warheads than it would kill, and, therefore, would not be considered to be lucrative.
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Minuteman Modernization Programs
The Air Force has pursued several programs that are designed to improve the accuracy and
reliability of the Minuteman fleet and to extend the missiles’ service lives. According to some
estimates, this effort could eventually cost $6-7 billion.34 This section describes several of the key
programs in this effort.
Propulsion Replacement Program (PRP)
The program began in 1998 and has been replacing the propellant, the solid rocket fuel, in the
Minuteman motors to extend the life of the rocket motors. A consortium led by Northrup
Grumman poured the new fuel into the first and second stages and remanufactured the third
stages of the missiles. According to the Air Force, as of early August, 2007, 325 missiles, or 72%
of the fleet, had completed the PRP program; this number increased to around 80% by mid-2008.
The Air Force purchased the final 56 booster sets, for a total of 601, with its funding in FY2008.
Funding in FY2009 supported the assembly of the remaining boosters. The Air Force expects to
complete the PRP program by 2013.35 In the FY2007 Defense Authorization Act (P.L. 109-364)
and the FY2007 Defense Appropriations Act (P.L. 109-289), the 109th Congress indicated that it
would not support efforts to end this program early. However, in its budget request for FY2010,
the Air Force indicated that FY2009 was the last year for funding for the program.
Guidance Replacement Program (GRP)
The Guidance Replacement Program has extended the service life of the Minuteman missiles’
guidance set, and improved the maintainability and reliability of guidance sets. It replaced aging
parts with more modern and reliable technologies, while maintaining the accuracy of the
missiles.36 Flight testing for the new system began in 1998, and, at the time, it exceeded its
operational requirements. Production began in 2000, and the Air Force purchased 652 of the new
guidance units. Press reports indicate that the system had some problems with accuracy during its
testing program.37 The Air Force eventually identified and corrected the problems in 2002 and
2003. According to the Air Force, 425 Minuteman III missiles were upgraded with the new
guidance packages as of early August, 2007. The Air Force had been taking delivery of 5-7 new
guidance units each month, for a total of 652 units. Boeing reported that it had delivered the final
guidance set in early February 2009. The Air Force has indicated that this program has achieved
full operational capability, and it did not plan to request any additional funding for FY2010 or
2011.
34 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
35 Sirak, Michael. Minuteman Fleet has Life Beyond 2020, Says Senior Air Force Space Official. Defense Daily. June
14, 2006.
36 LGM Minuteman III Modernization. Globalsecurity.org
37 Donnelly, John M. Air Force Defends Spending Half A Billion on Iffy ICBMs. Defense Week. September 10, 2001.
p. 1.
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Propulsion System Rocket Engine Program (PSRE)
According to the Air Force, the Propulsion System Rocket Engine (PSRE) program is designed to
rebuild and replace Minuteman post-boost propulsion system components that were produced in
the 1970s. The Air Force has been replacing, rather than repairing this system because original
replacement parts, materials and components are no longer available. This program is designed to
reduce the life-cycle costs of the Minuteman missiles and maintain their reliability through 2020.
Through FY2009, the Air Force had purchased 441 units for this program, at a cost of $128
million. It requested an additional 26.2 million to purchase another 96 units in FY2010 and $21.5
million to purchase 37 units in FY2011.
Rapid Execution and Combat Targeting (REACT) Service Life Extension Program
The REACT targeting system was first installed in Minuteman launch control centers in the mid-
1990s. This technology allowed for a significant reduction in the amount of time it would take to
re-target the missiles, automated routine functions to reduce the workload for the crews, and
replaced obsolete equipment.38 In 2006, the Air Force began to deploy a modernized version of
this system to extend its service life and to update the command and control capability of the
launch control centers. This program will allow for more rapid retargeting of ICBMs, a capability
identified in the Nuclear Posture Review as essential to the future nuclear force The Air Force
completed this effort in late 2006.
Safety Enhanced Reentry Vehicle (SERV)
As was noted above, under the SERV program, the Air Force plans to deploy MK21/W-87 reentry
vehicles removed from Peacekeeper ICBMs on the Minuteman missiles, replacing the older
MK12/W62 and MK12A/W78 reentry vehicles. To do this, the Air Force must modify the
software, change the mounting on the missile, and change the support equipment. According to
Air Force Space Command, the SERV program conducted three flight tests in 2005 and cancelled
a fourth test because the first three were so successful.39 The Air Force installed 20 of the kits for
the new reentry vehicles on the Minuteman missiles at F.E. Warren Air Force Base in 2006. The
process began at Malmstrom in July 2007 and at Minot in July 2008. As of early August 2007, 47
missiles had been modified. The Air Force purchase an additional 111 modification kits in
FY2009, for a total of 570 kits. This was the last year that it planned to request funding for the
program. It plans to complete the installation process by 2012.
This program will likely ensure the reliability and effectiveness of the Minuteman III missiles
throughout their planned deployments. The W-87 warheads entered the U.S. arsenal in 1986 and
were refurbished in 2005. This process extended their service life past 2025.40
38 LGM Minuteman III Modernization. Globalsecurity.org
39 Lt. Gen. Frank G. Klotz, Vice Commander, Air Force Space Command. Transcript of Speech to the National
Defense University Breakfast. June 13, 2006.
40 Tom Collina, Fact Sheet: U.S. Nuclear Modernization, Arms Control Association, Washington, D.C., January 5,
2009, http://www.armscontrol.org/USNuclearModernization.
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Solid Rocket Motor Warm Line Program
In the FY2009 Omnibus Appropriations Bill, Congress approved a new program known as the
Solid Rocket Motor Warm Line Program. According to Air Force budget documents, this program
is intended to “sustain and maintain the unique manufacturing and engineering infrastructure
necessary to preserve the Minuteman III solid rocket motor production capability” by providing
funding to maintain a low rate of production of motors each year. 41 The program received $42.9
million in FY2010 and produced motors for four Minuteman ICBMs. DOD has requested $44.2
million to produce motors for three additional ICBMs in FY2011.
Future Programs
The Air Force began to explore its options for a new missile to replace the Minuteman III in
2002, with the intent to begin deploying a new missile in 2018. It reportedly produced a “mission
needs statement” at that time, and then began an Analysis of Alternatives (AOA) in 2004.42 In
June 2006, Lt. General Frank Klotz indicated that, after completing the AOA, Space Command
had decided to recommend “an evolutionary approach to the replacement of the Minuteman III
capability,”43 which would continue to modernize the components of the existing missiles rather
than begin from scratch to develop and produce new missiles. He indicated that Space Command
supported this approach because it would be less costly than designing a new system “from
scratch.” With this plan in place, the Air Force now plans to maintain the Minuteman fleet
through 2020 and is examining those investments that might be needed to sustain it through 2030.
According to General Robert Kehler, the Commander-in-Chief of Air Force Space Command, the
missile should be viable throughout that time.44 At the same time, the Air Force has begun to
consider what a follow-on system to the Minuteman III might look like for the time frame after
2030.
Submarine Launched Ballistic Missiles
The U.S. fleet of ballistic missile submarines consists of 14 Trident submarines, each equipped to
carry 24 Trident missiles. The fleet currently carries a total of around 1,200 warheads.
By the early 1990s, the United States had completed the deployment of 18 Trident ballistic
missile submarines (SSBNs). Each of these submarines was equipped to carry 24 Trident
missiles, and each missile could carry up to 8 warheads (either W-76 warheads or the larger W-88
warheads on the Trident II missile). The Navy initially deployed 8 of these submarines at Bangor,
Washington, and all 8 were equipped with the older Trident I missile. It then deployed 10
submarines, all equipped with the Trident II missile, at Kings Bay, Georgia. During the 1994
Nuclear Posture Review, the Clinton Administration decided that the United States would reduce
41 http://www.saffm.hq.af.mil/shared/media/document/AFD-100128-067.pdf
42 Selinger, Mark. Minuteman Replacement Study Expected to Begin Soon. Aerospace Daily and Defense Report. June
25, 2004.
43 Lt. Gen. Frank G. Klotz, Vice Commander, Air Force Space Command. Transcript of Speech to the National
Defense University Breakfast. June 13, 2006.
44 Jason Simpson, “Kehler: Air Force Investigating Minuteman III Follow-On System,” Inside the Air Force, October
8, 2009. See, also, Jason Simpson, “Testers See no Problems With Minuteman III Missiles Lasting to 2030,” Inside the
Air Force, September 4, 2009.
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the size of its Trident fleet to 14 submarines, and that four of the older submarines would be
“backfit” to carry the Trident II missile.
The Bush Administration’s 2001 Nuclear Posture Review endorsed the plan to “backfit” 4 of the
Trident submarines so that all would carry Trident II missiles. It also indicated that, instead of
retiring the remaining 4 submarines, the Navy would convert them to carry conventional
weapons, and designated them “guided missile” submarines (SSGNs). The 2010 NPR also
endorsed a force of 14 Trident submarines, although it noted that it might reduce that force to 12
submarines in the latter half of this decade. For now, at least, the U.S. ballistic missile submarine
(SSBN) force consists of 14 Trident submarines, with 7 based at Bangor, Washington, 5 based at
Kings Bay, Georgia, and 2 in overhaul. This section describes many of the plans and programs
that are changing this force.
The SSGN Program
The Navy has completed the process of converting 4 Trident submarines (the USS Ohio, USS
Michigan, USS Florida, and USS Georgia) to carry conventional cruise missiles and other
conventional weapons. Reports indicate that the conversion process took approximately $1 billion
and two years for each of the 4 submarines. The SSGNs can each carry 154 Tomahawk cruise
missiles, along with up to 100 special forces troops and their mini-submarines.45
The first two submarines scheduled for this conversion were removed from the nuclear fleet in
early 2003. They were slated to receive their engineering overhaul, then to begin the conversion
process in 2004.46 The first to complete the process, the USS Ohio returned to service as an
SSGN in January 200647 and achieved operational status on November 1, 2007. According to the
Navy, the Georgia was scheduled for deployment in March 2008, and the other submarines were
scheduled to reach that status later in the year.48 According to Admiral Stephen Johnson, the
Director of the Navy’s Strategic Submarine Program (SSP), all four of the submarines had
returned to service by mid-2008, and two were forward-deployed on routine patrols.
The Backfit Program
As was noted above, both the 1994 and 2001 Nuclear Posture Reviews confirmed that the Navy
would “backfit” four Trident submarines so that they could carry the newer Trident II (D-5)
missile. This process not only allowed the Navy to replace the aging C-4 missiles, it also
equipped the fleet with a missile that has improved accuracy and a larger payload. With its greater
range, it would allow the submarines to operate in a larger area and cover a greater range of
targets. These characteristics were valued when the system was designed and the United States
sought to enhance its ability to deter the Soviet Union. The Bush Administration believed that the
45Connolly, Allison. For Four Subs, Its Good-bye Ballistic Missiles, Hello SEALs. Norfolk Virginia Pilot. December
18, 2004.
46 Ohio Class SSGN Tactical Trident. GlobalSecurity.org http://www.globalsecurity.org/military/systems/ship/ssgn-
726.htm
47 First Trident Submarine Converted. Associated Press. January 10, 2006.
48 U.S. Congress. Senate. Armed Services Committee, Subcommittee on Strategic Forces. Fiscal Year 2008 Strategic
Forces Program Budget. Hearing. Prepared statement of Mr. Brian R. Green, Deputy Assistant Secretary of Defense,
Strategic Capabilities, p. 6. March 28, 2007. See also, Guided Missile Submarine Ohio Ready for Deployment. Inside
the Navy, November 5, 2007.
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range, payload, and flexibility of the Trident submarines and D-5 missiles remained relevant in an
era when the United States may seek to deter or defeat a wider range of adversaries. The Obama
Administration has emphasized that, by providing the United States with a secure second strike
capability, these submarines enhance strategic stability.
Four of the eight Trident submarines based in Bangor, Washington (USS Alaska, USS Nevada,
USS Henry M. Jackson and USS Alabama) were a part of the backfit program. The Alaska and
Nevada both began the process in 2001; the Alaska completed its backfit and rejoined the fleet in
March 2002 and the Nevada did the same in August 2002. During the process, the submarines
underwent a pre-planned engineered refueling overhaul, which accomplishes a number of
maintenance objectives, including refueling of the reactor; repairing and upgrading some
equipment, replacing obsolete equipments, repairing or upgrading the ballistic missile systems,
and other minor alterations.49 The submarines also are fit with the Trident II missiles and the
operating systems that are unique to these missiles. According to the Navy, both of these efforts
came in ahead of schedule and under budget. The Henry M. Jackson and Alabama were
scheduled to compete their engineering overhaul and backfit in FY2006 and to reenter the fleet in
2007 and 2008.
The last of the Trident I (C-4) missiles was removed from the fleet in October 2004, when the
USS Alabama off-loaded its missiles and began the overhaul and backfit process. All the Trident
submarines currently in the U.S. fleet now carry the Trident II missile.50
Basing Changes
When the Navy first decided, in the mid-1990s, to maintain a Trident fleet with 14 submarines, it
planned to “balance” the fleet by deploying 7 Trident submarines at each of the two Trident bases.
The Navy would have transferred 3 submarines from Kings Bay to Bangor, after 4 of the
submarines from Bangor were removed from the ballistic missile fleet, for a balance of 7
submarines at each base. However, these plans changed after the Bush Administration’s Nuclear
Posture Review. The Navy has transferred 5 submarines to Bangor, “balancing” the fleet by
basing 9 submarines at Bangor and 5 submarines at Kings Bay. Because two submarines would
be in overhaul at any given time, this basing plan means that 7 submarines would be operational
at Bangor and 5 would be operational at Kings Bay.
According to unclassified reports, the Navy began moving Trident submarines from Kings Bay to
Bangor in 2002, and transferred the fifth submarine in September 2005.51 This change in basing
pattern apparently reflects changes in the international security environment, with fewer targets
within range of submarines operating in the Atlantic, and a greater number of targets within range
of submarines operating in the Pacific. In particular, the shift allows the United States to improve
its coverage of targets in China and North Korea.52 Further, as the United States modifies its
nuclear targeting objectives it could alter the patrol routes for the submarines operating in both
49 SSBN-726 Ohio-Class FBM Submarines, GlobalSecurity.org, http://www.globalsecurity.org/wmd/systems/ssbn-726-
recent.htm.
50 Morris, Jefferson. Older Trident Missiles to be Phased out by Fall, Admiral Says. Aerospace Daily and Defense
Report. June 17, 2005.
51 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
52 Ibid.
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oceans, so that a greater number of emerging targets would be within range of the submarines in a
short amount of time.
Warhead Issues
The Trident I (C-4) and Trident II (D-5) missiles can be equipped to carry up to 8 warheads each.
Under the terms of the START Treaty, the United States could remove warheads from Trident
missiles, and reduce the number listed in the database, a process known as downloading, to
comply with the Treaty’s limit of 6,000 warheads. The United States took advantage of this
provision as it reduced its forces under START, reducing to 6 warheads per missile on the 8
Trident submarines based at Bangor, Washington.53
The Navy has also reduced the number of warheads on the other Trident submarines, so that the
United States could reduce its forces to the 2,200 deployed warheads permitted under the
Moscow Treaty. The United States did not have to reach this limit until 2012, but it has already
done so. The United States has not, however, had to indicate how many warheads are deployed on
each missile; it can simply have to declare a total number of operationally deployed warheads on
all of its strategic nuclear delivery vehicles. The United States can continue to reduce the numbers
of warheads carried on its Trident missiles under the new START Treaty. Unlike START, which
attributed the same number of warheads to each missile of a given type, regardless of whether
some of the missiles carried fewer warheads, the new Treaty will count the precise number of
warheads deployed on each missile. This number will be listed in the treaty database, and the
parties will have opportunities to confirm that number with random, short-notice inspections.
Moreover, the United States will not have to alter the platforms in the missiles, so it could restore
warheads to its Trident missiles if circumstances changed.
Modernization Plans and Programs
The Navy initially planned to keep Trident submarines in service for 30 years, but has now
extended that time period to 42 years. This extension reflects the judgment that ballistic missiles
submarines would have operated with less demanding missions than attack submarines, and
could, therefore, be expected to have a much longer operating life than the expected 30 year life
of attack submarines. Therefore, since 1998, the Navy has assumed that each Trident submarine
would have an expected operating lifetime of at least 42 years, with two 20-year operating cycles
separated by a two-year refueling overhaul.54 The Navy has also pursued a number of programs to
ensure that it has enough missiles to support this extended life for the submarines.
Trident Missile Production
The Navy purchased 461 Trident II (D-5) missiles through FY2009. After finalizing the plan to
deploy all 14 Trident submarines with D-5 missiles, the Navy extended Trident production
through 2013, and now expects to purchase 561 Trident missiles, at a rate of 12-24 missiles per
53 Even though four of these submarines are being converted to SSGNs, they still count under the START Treaty
because they still have SLBM launch tubes. Each of those tubes count as six warheads. See U.S. Department of State.
Bureau of Verification, Compliance, and Implementation. START Aggregate Number of Strategic Offensive Arms.
April 1, 2006.
54 SSBN Ohio-Class FBM Submarines. GlobalSecurity.org.
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year.55 The Navy expects to maintain a fleet of 12 operational Trident submarines, with 24
missiles on each submarine, but it would need more than the 288 missiles that would fill these
submarines. Around 50 of the missiles would be available for use by Great Britain in its Trident
submarines. The remainder would support the missile’s test program throughout the life of the
Trident system. The Navy requested $220 million towards the purchase of Trident missiles in
FY2007, $211.5 million in FY2008, $186.3 million in FY2009, and $162.4 million in FY2010.
Trident Missile Life Extension
The Navy has also begun a life extension program for the Trident II missiles, so that they will
remain capable and reliable throughout the 45-year life of the Trident submarines. The Navy
requested nearly $700 million to support this program in FY2007, $457.7 million in FY2008,
$487.4 million in FY2009 and $524.5 in FY2010. According to the Navy, this funding will
sustain efforts to redesign the guidance system and missile electronics to extend the life of the
missiles.56 The Navy expects the refurbished missiles to reach their IOC in 2013.
W76 Warhead Life Extension
The overwhelming majority of Trident missiles are deployed with the MK4/W76 warhead, which,
according to unclassified estimates, has a yield of 100 kilotons.57 It is nearing the end of its
service life and is currently undergoing a life extension program that is designed to enhance its
capabilities. According to some reports, the Navy had initially planned to apply this program to
around 25% of the W76 warheads, but has increased that plan to cover more than 60% of the
stockpile. The life extension program is intended to add 30 years to the warhead life “by
refurbishing the nuclear explosive package, the arming, firing, and fusing system, the gas transfer
system, and associated cables, elastomers, valves, pads, cushions, foam supports, telemetries, and
other miscellaneous parts.” In FY2010, Congress appropriated $223.2 million for this program.58
Several questions have come up during the life extension program. For example, some weapons
experts have questioned whether the warhead’s design is reliable enough to ensure that the
warheads will explode at its intended yield.59 In addition, in June 2006, an inspector general’s
report from the Department of Energy questioned the management practices at the National
Nuclear Security Administration (NNSA), which is responsible for the life extension program,
arguing that management problems had led to delays and created cost overruns in the program.
This raised questions about whether NNSA would be able to meet the September 2007 delivery
date for the warhead,60 and, when combined with other technical issues delayed the delivery of
the first W-76 warhead until August 2008. The Navy accepted the first refurbished warhead into
55 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
56 U.S. Department of Defense. Department of the Navy. Fiscal Year 2007Budget Estimate Submission. Justification of
Estimates. February 2006. p. 13.
57 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
58 Elaine M. Grossman, “Nuclear Bomb Update Effort Slowed by Posture Review, Science Studies,” Global Security
Newswire, January 19, 2010.
59 Fleck, John. Flaws Seen in Sub-Launched Nuclear Warhead. Albuquerque Journal. July 8, 2004.
60 Costa, Keith J. IG: Project Weaknesses put W-76 Warhead Refurbishment Plan at Risk. InsideDefense.Com June 8,
2006.
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the stockpile in August 2009.61 NNSA had planned to eventually phase out the life extension
program, and use the new Reliable Replacement Warhead program to develop a replacement for
the W-76 warhead,62 but Congress has not funded the studies supporting the development of the
RRW.
Conventional Trident Modification
In the report of the 2006 Quadrennial Defense Review, the Pentagon called for the deployment of
conventional warheads on a portion of its Trident SLBMs.63 According to DOD’s plan, the Navy
would deploy two Trident missiles on each submarine with conventional warheads and deploy 4
warheads deployed on each of these missiles, for a total force of 96 conventional warheads. This
would provide the United States with the capability to launch conventional warheads against
targets around the world in less than an hour, a capability that does not now exist unless U.S.
forces are forward-based in the region where the targets might be. This is a part of STRATCOM’s
plan for the Prompt Global Strike mission. The Navy requested $127 million for FY2007 to begin
this program, but Congress did not authorize or appropriate the funding in the FY2007 Defense
Authorization or Defense Appropriations bills, instead questioning the need for and intentions of
the program, while raising concerns about the possibility that other nations might misinterpret the
launch of a conventional Trident missile.
The Navy requested $175 million for this program in FY2008. The House Armed Services
Committee, in its version of the FY2008 Defense Authorization Bill (H.R. 1585, H.Rept. 110-
146), approved the request for $126.4 million for continued research and development on the
reentry vehicle, and authorized $16 million for procurement, but reduced the budget request by
$33 million, withholding all funds for long-lead procurement. The Senate Armed Services
Committee, in its version of the FY2008 Defense Authorization Bill (S. 1547, S.Rept. 110-77),
recommended that no funding be provided specifically for the CTM program, and that all the
funding for the CTM and other “prompt global strike” programs, a total of $208 million be
pooled to support a “coordinated look at a variety of kinetic non-nuclear concepts is necessary to
address the feasibility of a prompt global strike.” In the final version of the Defense Authorization
Bill for FY2008 (H.Rept. 110-477), the Conference Committee adopted that Senate’s approach,
combining the funding in a single account. But, as the Defense Appropriations Bill had done, the
Conference Report on the Defense Authorization Bill limited this funding to $100 million. In
FY2009, the funding remains in a single account, and Congress continued to reject separate
funding for the CTM program.
Future Programs
The Navy has initiated studies into options for a replacement for the Trident submarine.
According to Admiral Stephen Johnson, the Navy would have to begin construction of its new
submarine by 2019 so that it could begin to enter the fleet in 2029.64 The Tridents submarines will
61 “Navy Receives First Refurbished W-76 Warheads,” Global Security Newswire, November 6, 2009.
62 U.S. Congress. Senate. Armed Services Committee, Subcommittee on Strategic Forces. Fiscal Year 2008 Strategic
Forces Program Budget. Hearing. March 28, 2007.
63 For details, see, CRS Report RL33067, Conventional Warheads for Long-Range Ballistic Missiles: Background and
Issues for Congress, by Amy F. Woolf.
64 RADM Stephen Johnson, Director, Navy Strategic Programs Office. Speech at the NDU/NDIA Seminar Series, June
23, 2009.
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begin to retire in 2027, and the new submarines must begin to enter the fleet by 2029, before the
number of Trident submarines falls below 12.65 In April 2009, Secretary of Defense Robert Gates
announced that the Navy would formally begin the replacement program for the Trident
submarines, known as the SSBN(X) in FY2010.66
The Navy is currently conducting development and design work on the new submarine.67 The
current plans call for a fleet of 12 submarines, with perhaps 16-20 launch tubes on each
submarine. The program received $497.4 million in research and development funding in the
Navy’s FY2010 budget, and the Navy’s proposed FY2011 budget requests an additional $672.3
million in research and development funding for the program. Navy plans call for procuring the
first SSBN(X) in FY2019, with advance procurement funding for the boat beginning in FY2015.
The Navy has estimated that each submarine in this program could cost $6 billion to $7 billion in
FY2010 dollars; some have estimated that the total cost could reach $80 billion.68
Bombers
B-1 Bomber
The Air Force began to deploy the B-1 bomber in the mid-1980s and eventually deployed a fleet
of 96 aircraft. After several crashes, the Air Force was left with 92 bombers in 2001. It has sought
to retire 30 of the aircraft, leaving a force of 62 bombers, but has met resistance from Congress.
The B-1 served exclusively as a nuclear delivery vehicle through 1991, carrying short-range
attack missiles and gravity bombs. Because these bombers were not equipped to carry nuclear-
armed air-launched cruise missiles, each counts as a single delivery vehicle and a single warhead
under START. In 1993, the Air Force began to convert the B-1 bombers to carry conventional
weapons. This process was completed in 1997 and the B-1 bomber is no longer equipped to carry
nuclear weapons, although it still counts against the START limits. Neither the bomber nor its
weapons count against the limits in the Moscow Treaty. The bomber has contributed to U.S.
conventional operations in Afghanistan and Iraq.
B-2 Bomber
The Air Force has 20 B-2 bombers, based at Whiteman AFB in Missouri.69 The B-2 bomber can
carry both B-61 and B-83 nuclear bombs, but is not equipped to carry cruise missiles. It can also
carry conventional weapons, and has participated in U.S. military campaigns from Bosnia to Iraq.
It is designed as a “low observable” aircraft, and was intended to improve the U.S. ability to
65 Christopher J. Castelli, “Navy Confronts $80 Billion Cost of New Ballistic Missile Submarines,” Inside Defense,
November 3, 2009.
66 U.S. Department of Defense, Briefing by Defense Secretary Robert Gates and Marine Corps Gen. James Cartwright,
Vice Chairman of the Joint Chiefs of Staff, Washington, D.C., April 6, 2009, http://insidedefense.com/secure/
data_extra/html3/dplus2009_0893_3.htm.
67 For more details on this program see CRS Report R41129, Navy SSBN(X) Ballistic Missile Submarine Program:
Background and Issues for Congress, by Ronald O'Rourke.
68 Christopher J. Castelli, “Navy Confronts $80 Billion Cost of New Ballistic Missile Submarines,” Inside Defense,
November 3, 2009.
69 A B-2 bomber crashed on take-off from Anderson Air Force Base on Guam in late February 2008, reducing the
number of deployed bombers from 21 to 20.
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penetrate Soviet air defenses. However, according to recent reports, the Air Force is
contemplating modifying the bomber so that it can also serve as a standoff-capable platform. In
October 2009, General Donald Alston, the Assistant Chief of the Air Force for Strategic
Deterrence and Nuclear Integration, indicated that the B-2 would need significant upgrades to
contribute to this mission.70
Weapons
According to unclassified estimates, the United States has around 550 B-61 and B-83 bombs.71
The B61-11, a modification developed in the 1990s, has a hardened, modified case so that it can
penetrate some hardened targets, although probably not those encased in steel and concrete. The
B-83 bomb is a high yield weapon, that is also designed to destroy hardened targets, such as
ICBM silos. The National Nuclear Security Administration reported that it had completed its life
extension program for two versions of the B-61 bomb in early 2009. The B-2 bomber can also
carry the B-61-Mod 7, a version that has not yet been through a life-extension program. Reports
indicate that this version would be included in the “Mod-12” life extension program for the B-61,
along with two other tactical versions of the bomb. However, in the FY2010 Energy and Water
Appropriations Bills, Congress reduced funding for this program and limited the available
funding to modifications of the bombs’ non-nuclear components. These restrictions were
reportedly designed to slow the program until the Administration reported, through the Nuclear
Posture review, on its future plans for U.S. nuclear weapons programs.72
The Obama Administration strongly supported the life extension program for the B-61 bomb in
the Nuclear Posture Review. The report indicated that “the Administration will fully fund the full
scope LEP study and follow-on activities for the B-61 bomb ... to ensure first production begins
in FY2017.” The NPR noted that life extension program for the B-61 bomb, which would include
enhancing safety, security, and use control, would also support U.S. extended deterrence goals by
allowing the United States to retain the capability to forward-deploy U.S. nuclear weapons on B-2
bombers and tactical fighter-bombers.73
B-52 Bomber
The Air Force maintains around 85 B-52H aircraft at two bases, Barksdale, Louisiana and Minot,
North Dakota.74 The Air Force began to retire the first of 18 B-52 bombers scheduled for
retirement at the end of July 2008.75 The B-52 bomber, which first entered service in 1961, is
equipped to carry nuclear or conventional air-launched cruise missiles and nuclear-armed
advanced cruise missiles. The B-52 bombers can also deliver a wide range of conventional arms.
70 Marina Malenic, “With Nex-Gen Bomber IN HOlding Pattern, Air Force Wants Further B-2 Mods,” Defense Daily,
October 21, 2009.
71 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
72 Elaine M. Grossman, “Nuclear Bomb Update Effort Slowed by Posture Review, Science Studies,” Global Security
Newswire, January 19, 2010.
73 U.S. Department of Defense, Nuclear Posture Review, Washington , D.C., April 6, 2010, p. 27,
http://www.defense.gov/npr/docs/2010%20Nuclear%20Posture%20Review%20Report.pdf.
74 A B-52 bomber crashed off the coast of Guam in July 2008.
75 U.S. Air Force, Minot Air Force Base, Office of Public Affairs. B-52H Reaches Retirement. July 30, 2008.
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The Air Force has proposed cutting the B-52 fleet on many occasions in the last 15 years. For
example, when the United States identified the force structure that it would deploy under the
START Treaty, it indicated that it would only seek to retain 76 B-52 bombers. Congress, however,
rejected the Clinton Administration’s proposal, and the United States retained the full fleet of 94
aircraft.
The 2006 Quadrennial Defense Review called for a significant change to the B-52 fleet, reducing
it from 94 to 56 aircraft. The budget request for FY2007 indicated that the Air Force planned to
retire 18 bombers in FY2007 and 20 in FY2008. At the same time, the QDR called for continuing
improvements to the B-1, B-2, and B-52 bombers’ conventional capabilities using the funds that
were saved by the retirement of the 38 aircraft. The Air Force has argued that it can reduce the
number of deployed bombers, without reducing the overall capabilities of the bomber fleet,
because these new weapons have “raised the efficiency” of the bomber platform. At hearings
before the Senate Armed Services Committee, General James E. Cartwright, the Commander of
STRATCOM, noted that “the next generation weapons that we’re fielding, these air-launched
cruise missiles, the joint direct attack munitions, et cetera, are much more efficient than they were
in the past.”76 General Cartwright also indicated that, in spite of the reduced size of the fleet, the
Air Force would continue to deploy B-52 bombers at two bases.
During the FY2007 budget cycle, Congress rejected the Pentagon’s proposals for at least part of
the B-52 fleet. The House, in its version of the FY2007 Defense Authorization Bill, prohibited the
Air Force from retiring any of the B-52 aircraft, and mandated that it maintain at least 44 “combat
coded” aircraft until the Air Force began to replace the B-52 with a new bomber of equal or
greater capability. It stated, as a part of its rationale for this rejection, that it appeared the
reduction was based on the reduced need for nuclear-capable bombers and did not take into
consideration a growing need for long-range conventional strike capabilities.77 The Senate agreed
to permit the Air Force to retire 18 B-52 aircraft, but stated that it expected no further reduction in
the size of the force, noting that a further reductions might “prevent our ability to strike the
required conventional target set during times of war.”78 The Conference Committee (H.R. 5122,
Sec. 131) combined these two provisions, allowing the retirement of no more than 18 aircraft
after the submission of a report, and mandating that the Air Force retain at least 44 “combat
coded” aircraft. These restrictions are to remain in place until 2018, or until a new long-range
strike aircraft “with equal or greater capability than the B-52H model aircraft” attained initial
operational capability, if that occurred first. Congress also stated that no funds could be spent to
retire any B-52 aircraft until the Secretary of the Air Force submitted a report to Congress that
described the Air Force plan for the modernization of the B-52, B-1, and B-2 bomber fleets; how
many bombers would be assigned two nuclear and conventional missions if the United States had
to execute “two overlapping ‘swift defeat’ campaigns;” a justification of the cost and projected
savings of any reductions to the B-52H bomber aircraft fleet; the life expectancy of each bomber
aircraft to remain in the bomber force structure and the capabilities of the bomber force structure
that would be replaced by a new bomber aircraft.
76 U.S. Senate, Committee on Armed Services, Hearing on Global Strike Plans and Programs. Testimony of James E.
Cartwright, Commander U.S. Strategic Command. March 29, 2006.
77 U.S. Congress. House. Committee on Armed Services. National Defense Authorization Act for Fiscal Year 2007.
H.Rept. 109-452. May 5, 2006. p. 103.
78 U.S. Congress Senate. National Defense Authorization Act for Fiscal Year 2007. S.Rept. 109-254. May 9, 2006. p.
94.
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The Air Force indicated that the report on the bomber fleet would be ready in the fall of 2007.
Further, in testimony before the Armed Services Committee, the Air Force indicated that it still
planned to reduce the B-52 fleet to 56 aircraft, with 32 combat coded aircraft included in the fleet.
But, in recognition of the congressional mandate, it was seeking a way to maintain 44 combat
coded aircraft, the minimum set by Congress, within the smaller fleet of 56 aircraft. It also stated
that it planned to store the 20 aircraft it wanted to retire in FY2008 on ramps at Barksdale Air
Force Base; the aircraft would be kept in serviceable condition, but would not receive any
capabilities upgrades.79 Congress once again rejected this proposal. In the FY2008 Defense
Authorization Bill (H.R. 1585, Sec. 137), Congress mandated that the Air Force maintain a fleet
of 74 B-52 bombers, with no less than 63 in the Primary Aircraft inventory and 11 backup
aircraft. Two additional aircraft would be designated as “attrition reserve.” The Conference
Committee indicated that the Members agreed that a fleet of fewer than 76 aircraft would be
insufficient to meet long-range strike requirements.
The growing interest in long-range strike capabilities, and the continuing addition of precision
conventional weapons to these aircraft, demonstrates that the Pentagon and STRATCOM view
the U.S. bomber fleet as essential to U.S. conventional weapons capabilities. Further, the need for
long-range strike capabilities, rather than an interest in maintaining the nuclear role for
bombers,80 appeared to be driving decisions about the size and structure of the bomber fleet.
There are some indications that, during the discussions on the 2006 QDR, some in the Pentagon
argued that the all the B-52 bombers should be removed from the nuclear mission. Moreover, in
November 2008, Secretary of the Air Force Michael Donley noted that the role that the bombers
play in nuclear deterrence could be reduced in the future, if the U.S. and Russia negotiate further
reductions in their nuclear arsenals.
This focus began to shift, however, in 2008. Several recent studies have noted that a lack of
attention paid in the Air Force and, more broadly, in DOD, to the bombers’ nuclear mission seems
to be one of the factors that led to the episode in August 2007, when a B-52 bombers flew from
Minot to Barksdale with six cruise missiles that carried live nuclear warheads. 81 The Air Force is
pursuing a number of organizational and procedural changes to increase its focus on the nuclear
mission and “reinvigorate” its nuclear enterprise. For example, it plans to “stand-up” a B-52
bomber squadron that will focus specifically on the nuclear mission.82 This new unit would add
10 bombers to the 12 already deployed at Minot. While all the B-52 bomber crews and aircraft
will retain their nuclear roles, this added squadron will participate in a greater number of nuclear
exercises and training missions. The aircraft in the squadron will rotate from other missions, but
will remain designated as the nuclear squadron for full year. The Air Force hopes this construct
will improve not only the operational proficiency of the crews, but also their morale and their
confidence in the value of the nuclear mission. The Air Force expects the new squadron to begin
its operations late in 2009 or early in 2010.
79 U.S. Congress. Senate. Armed Services Committee, Subcommittee on Strategic Forces. Hearing on the Fiscal Year
2008 Strategic Forces Program Budget. Statement of Major General Roger Burg. March 28, 2007. p. 8.
80 Carlo Munoz, “Donley: Role of Nuclear Bomber Fleet Could Be Curtailed,” Inside the Air Force, November 14,
2008.
81 For a detailed review of this incident see, Warrick, Joby and Walter Pincus. The Saga of a Bent Spear. Washington
Post. September 23, 2007.
82 Marcus Weisgerber, “USAF To Activate Rotational Nuclear Bomber Squadron Next Month,” Inside Defense,
September 26, 2008.
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With this change, Secretary of Defense Gates stated, in April 2009, that the Air Force now
planned to retain 76 B-52 bombers. The 2010 Nuclear Posture Review also indicated that the
United States currently has 76 B-52 bombers equipped to carry nuclear weapons. It determined
that the Air Force would retain nuclear-capable bombers, but it would also convert some B-52s to
a conventional-only role.
Weapons
The B-52 bomber is equipped to carry both the Air-Launched cruise missile (ALCM) and
Advanced Cruise Missile (ACM). The ACM reportedly has a modified design with a lower radar
cross-section, making it more “stealthy” than the ALCM. According to Air Force figures, the
United States has 1,142 ALCMs and 394 ACMs.83 Although these weapons represent a majority
of the weapons that U.S. bombers could carry on nuclear missions, the Department of Defense
recently decided to retire many of these missiles. In his statement to the Senate Armed Services
Committee’s Subcommittee on Strategic Forces, Major General Roger Burg indicated that this
study had concluded, and the Secretary of Defense had directed, that the Air Force retire all the
Advanced Cruise Missiles, although some could be converted to carry conventional warheads,
and reduce the ALCM fleet to 528 cruise missiles. The excess ALCMs will also be eliminated,
and the remaining missiles would be consolidated at Minot Air Force Base. With all the ALCMs
consolidated at Minot Air Force Base, the bombers at Barksdale may no longer be included in the
nuclear mission.
Both the ALCM and ACM were set to undergo life-extension programs so that they could remain
in service through 2030.84 Both cruise missiles also carry the W-80 warhead, which was
scheduled to for a life-extension program. However, the Department of Defense no longer plans
to support the W-80 refurbishment program.85 Moreover, the remaining ALCMs will reach the
end of their service lives within the next 10-20 years.
The Air Force plans to begin an assessment of alternatives (AOA) in August or September
FY2010 for a future “long-range stand-off vehicle” that might replace the existing ALCM.
According to the 2010 NPR, this AOA will inform decisions in FY2012 about whether and how
to replace the current ALCM. In addition, the FY2011 DOD budget contains $3.63 million for the
Air Force “to complete ongoing technical studies on a new cruise missile.” The budget also
indicates that research and development funding could increase sharply in the 2013-2015 time
frame, after the completion of the AOA. Air Force officials estimate that a new ALCM could
eventually cost $1.3 billion.86
83 The Air Force also has 289 ALCMs that have been converted to carry conventional warheads (CALCMs). See
Michael Sirak. DOD Studies Future Role of Nuclear-Armed Cruise Missiles. Defense Daily, March 30, 2006.
84 Robert S. Norris and Hans M. Kristensen. U.S. Nuclear Forces, 2006. Bulletin of the Atomic Scientists.
January/February 2006.
85 According to S.Rept. 109-274, Energy and Water Appropriations Bill 2007, the Nuclear Weapons Council and
Department of Defense no longer support the W80 Life Extension activities. As a result, both the House (H.R. 5427)
and Senate Appropriations Bills eliminate funding for this effort.
86 Elaine M. Grossman, “Pentagon Eyes More than $800 Million for New Nuclear Cruise Missile,” Global Security
Newswire, March 9, 2010.
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Future Bomber Plans
The Air Force has also begun to plan for the development of a new strategic bomber. It initially
planned to introduce the new bomber into the fleet around 2018. According to former Air Force
Secretary Michael Wynne, the service was seeking a bomber with not only stealth capabilities and
long range, but also one with “persistence,” one that could “stay airborne and on call for very
long periods.”87 The start of the study on a new bomber, known as an Analysis of Alternatives
(AOA) had been delayed by a dispute over whether the study should stand alone or be merged
with another AOA on prompt global strike (PGS). While a future bomber could be a part of the
PGS mission, other systems, such as hypersonic technologies and missiles, would also be a part
of the effort to strike anywhere around the world at long range. General Cartwright, the former
head of STRATCOM, reportedly supported a plan to merge the two efforts, so that the
considerations of capabilities for a new bomber would be measured along side other systems,
both to balance the force and avoid redundancy across the force.88 On the other hand, the former
Air Force Chief of Staff, General T. Michael Moseley, reportedly preferred to keep the two
studies separate. He argued that a bomber with long-range strike capabilities must have
“persistent, survivable, and penetrating capabilities” while a platform with PGS capabilities could
be “standoff weapon that is very, very fast.”89 This position reportedly prevailed, with the Air
Force deciding, in May 2006, to keep the two studies separate.90
This dispute reveals wide-ranging differences, within the Air Force and Pentagon, about the goals
for and capabilities that should be sought in a new bomber program.91 The dispute focused,
however, on conventional capabilities; it seems to be almost a foregone conclusion that nuclear
capabilities, or the need for a bomber leg of the nuclear triad, will not drive the discussion or
analysis.
In early May 2007, the Air Force indicated that it had decided that the next generation bomber
would be manned and subsonic, although it would incorporate some stealth characteristics.92 It
decided that it would not pursue supersonic capabilities, or an unmanned option, to contain costs
and maintain the capabilities of the future aircraft. In October 2008, Air Force Secretary Michael
Donley indicated that the new bomber would also be capable of carrying nuclear weapons.93
However, on April 6, 2009, in a briefing describing the FY2010 defense budget, Secretary of
Defense Robert Gates stated that the Air force would not “pursue a development program for a
follow-on Air Force bomber until we have a better understanding of the need, the requirement and
87 Christie, Rebecca. Air Force To Step Up New Bomber Search in Next Budget. Wall Street Journal. June 29, 2006.
88 Grossman, Elaine M. Cartwright Wants to See Strike Studies Await “Discovery” Process. InsideDefense.Com. April
6, 2006.
89 Bennet, John T. Internal Squabbles Holding Up Bomber Study, USAF Official Says. InsideDefense.com. April 21,
2006.
90 Matishak, Martin. Long-Range, Prompt Global Strike Studies Will Remain Separate. InsideDefense.com. June 16,
2006.
91 For more details on the proposed bomber, see CRS Report RL34406, Air Force Next-Generation Bomber:
Background and Issues for Congress, by Jeremiah Gertler.
92 Sirak, Michael. Air Force Identifies Manned, Subsonic Bomber as Most Promising 2018 Option. Defense Today.
May 2, 2007.
93 Carlo Munoz, “Donley: Next Generation Bomber Will Be Nuclear Capable by 2018,” Inside the Air Force, October
31, 2008.
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the technology.”94 Specifically, he suspended the program until DOD completes the QDR and
Nuclear Posture Review. In September 2009, General Norton Schwartz, the Chief of Staff of the
Air Force, acknowledged that the Air Force is still seeking to develop a new “long-range strike”
aircraft.95 Moreover, Secretary of Defense Gates has reportedly supported efforts to develop a
new platform for this mission. Its possible that this new airplane would serve as both a bomber
and a reconnaissance aircraft.96
The 2010 Quadrennial Defense Review, published in February 2010, indicated that the Air Force
is currently reviewing options for fielding survivable, long-range surveillance and strike aircraft
as part of a comprehensive, phased plan to modernize the bomber force.”97 The report also notes
that Secretary of Defense Gates ordered a follow-on study to the QDR to determine “what
combination of joint persistent surveillance, electronic warfare, and precision-attack capabilities,
including both penetrating platforms and stand-off weapons, will best support U.S. power
projection operations over the next two to three decades.” Although the study is just beginning,
the DOD budget request for 2011 includes $200 million for the new bomber, and DOD
documents indicate that expenditures on the bomber could total $1.74 billion through 2015.98
Secretary Gates has indicated that he expects the Air Force to field the next generation bomber in
the late 2020s.99
Issues for Congress
This report focuses on the numbers and types of weapons in the U.S. strategic nuclear force
structure. It does not address the broader question of why the United States chooses to deploy
these numbers and types of weapons, or more generally, the role that U.S. nuclear weapons play
in U.S. national security strategy. This question is addressed in other CRS reports.100 However, as
the Obama Administration reviews and possibly revises the plans for U.S. nuclear force structure,
Congress could address broader questions about the relationship between these forces and the role
of nuclear weapons.
Force Size
The Bush Administration argued that, because the United States and Russia are no longer
enemies, the United States would not size or structure its nuclear forces simply to deter the
94 94 U.S. Department of Defense, Briefing by Defense Secretary Robert Gates and Marine Corps Gen. James
Cartwright, Vice Chairman of the Joint Chiefs of Staff, Washington, D.C., April 6, 2009, http://insidedefense.com/
secure/data_extra/html3/dplus2009_0893_3.htm.
95 Otto Kreisher, “New Long-Range Strike Aircraft Still on Air Force’s Radar,” National Journal’s CongressDaily AM,
September 15, 2009.
96 Marina Malenic, “DOD Officials Examining “Full Menu” of Long-Range Strike Options in Bomber Review,”
Defense Daily, October 7, 2009.
97 U.S. Department of Defense, Quadrennial Defense Review Report, Washington, D.C., February 2010, p. 33,
http://www.defense.gov/qdr/images/QDR_as_of_12Feb10_1000.pdf.
98 Elaine M. Grossman, “Pentagon Eyes More than $800 Million for New Nuclear Cruise Missile,” Global Security
Newswire, March 9, 2010.
99 Andrea Shalal-Esa, “Gates Sees New U.S. Bomber Fielded in 2020s,” Reuters, February 2, 2010.
100 See, for example, CRS Report RL31623, U.S. Nuclear Weapons: Changes in Policy and Force Structure, by Amy
F. Woolf.
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“Russian threat.” Instead, nuclear weapons would play a broader role in U.S. national security
strategy. The Obama Administration, in contrast, noted that there is a relationship between the
size of the U.S. arsenal and the size of the Russian arsenal. The 2010 NPR states that “Russia’s
nuclear force will remain a significant factor in determining how much and how fast we are
prepared to reduce U.S. forces. Because of our improved relations, the need for strict numerical
parity between the two countries is no longer as compelling as it was during the Cold War. But
large disparities in nuclear capabilities could raise concerns on both sides and among U.S. allies
and partners, and may not be conducive to maintaining a stable, long-term strategic relationship,
especially as nuclear forces are significantly reduced.”101
The 2001 Nuclear Posture review determined that the United States would need to maintain
between 1,700 and 2,200 operationally deployed nuclear warheads. The Bush Administration also
indicated that the United States would maintain in storage many of the warheads removed from
deployed forces, and would maintain the capability to restore some of these warheads to the
deployed forces to meet unexpected contingencies. The Obama Administration concluded that the
United States could reduce its forces to 1,550 deployed warheads, but it also plans to retain the
capability to restore warheads to its deployed forces. It also plans to retain many warheads in
storage, although it has indicated that the size of the total stockpile could decline as the United
States reduces its deployed forces to the New START limits.102
Some analysts have questioned why the United States must maintain such a large force of nuclear
weapons. They have questioned whether the United States would attack with such a large number
of weapons if its own national survival were not at risk, and they note that only Russia currently
has the capability to threaten U.S. national survival. They assert that the United States could
likely meet any other potential contingency with a far smaller force of nuclear weapons. Some
have concluded, instead, that the United States could maintain its security with a force of between
500 and 1,000 warheads.103
The Bush Administration disputed this view, noting that the United States has other potential
adversaries, and, even if these nations do not possess thousands of nuclear warheads, some may
expand their nuclear forces or chemical and biological capabilities in the future. And, it asserted
that the need to assure allies and dissuade potential adversaries could require a force of significant
size, regardless of the number of potential targets a nation might possess.
The Obama Administration has indicated that the United States may be able to reduce its numbers
of deployed and nondeployed warheads further, but that it should do so in parallel with Russia. It
indicated, in the 2010 NPR, that “large disparities in nuclear capabilities could raise concerns on
both sides and among U.S. allies and partners, and may not be conducive to maintaining a stable,
long-term strategic relationship.”104
101 U.S. Department of Defense, Nuclear Posture Review, Washington, D.C., April 6, 2010, p. 30,
http://www.defense.gov/npr/docs/2010%20Nuclear%20Posture%20Review%20Report.pdf.
102 On May 3, 2010, the Obama Administration announced that the United States has 5,113 warheads in its stockpile of
nuclear weapons. This number includes the deployed warheads, active nondeployed warheads and inactive
nondeployed warheads. For more information, see http://www.defense.gov/npr/docs/10-05-
03_Fact_Sheet_US_Nuclear_Transparency__FINAL_w_Date.pdf.
103 See, for example, Sidney D. Drell and James E. Goodby. What Are Nuclear Weapons For? Recommendations for
Restructuring U.S. Strategic Nuclear Forces. Arms Control Association, Updated October 2007.
104 U.S. Department of Defense, Nuclear Posture Review, Washington, D.C., April 6, 2010, p. 30,
http://www.defense.gov/npr/docs/2010%20Nuclear%20Posture%20Review%20Report.pdf.
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Force Structure
When the Bush Administration announced the results of the Nuclear Posture Review, it indicated
that the United States would retain a triad of ICBMs, SLBMs, and heavy bombers for the
foreseeable future. The Obama Administration also offered continuing support for the retention of
the strategic triad. Nevertheless, the Obama Administration has indicated that it may convert a
portion of the U.S. bomber fleet to conventional-only missions.
As was noted above, most discussions about the bomber force focus on how many bombers, and
what types of bomber weapons, the United States needs to bolster its conventional long-range
strike capability. There is little, if any, discussion about the role that bombers may play in either
nuclear deterrence, or, if deterrence fails, in the launch of U.S. nuclear weapons. It is not
surprising that some in the Air Force and Pentagon, and some outside government have
questioned the continuing need for nuclear-capable bombers. 105
The Obama Administration has not yet specified how many ICBMs it will retain in the U.S. force,
although this information may be forthcoming soon. Analysts have often argued, and the 2010
NPR affirmed, that single-warhead ICBMs bolster crisis stability, and discourage efforts by an
adversary to launch a disarming first strike, because the cost of the strike, as measured by the
number of attacking warheads, would exceed the benefits, as measured by the number of
warheads destroyed. But this calculus is not dependent on the number of ICBMs in the fleet.106
The Trident fleet seems less vulnerable to reductions. The Obama Administration has indicated
that it plans to retain 14 Trident submarines, at least through 2015, and then may reduce to 12
submarines. Moreover, the New START Treaty allows the United States to continue to reduce the
warheads on each missile. It also allows the United States to eliminate some of the launch tubes
by simply removing the gas generators that assist in the launch of the missiles. As a result, the
United States will have a significant amount of flexibility in apportioning warheads among its
SSBNs, and will almost certainly not have to eliminate any submarines to meet the new START
limits. As a result, with its ability to remain invulnerable to detection and attack, and with the
increasing accuracy and reliability of its missiles and warheads, the Trident fleet will continue to
represent the “backbone” of the U.S. nuclear force.
The United States does not plan to alter the basic structure of its Trident fleet; it will continue to
deploy its submarines at two bases, with a portion of the fleet deployed in the Atlantic Ocean and
a portion deployed in the Pacific Ocean. However, if the United States reduces the size of its
nuclear arsenal significantly below the limits in the New START Treaty, the United States may
find it difficult to retain its “triad” of nuclear delivery vehicles. P residents Obama and Medvedev
have pledged to reduce nuclear weapons in a “step-by-step” process, with additional reductions
coming in a future treaty. Most analysts who propose deep reductions, to perhaps 1,000 nuclear
warheads, readily acknowledge that these reductions could affect the U.S. triad, and support
changes in the U.S. force structure.
105 For a recent analysis of the possible future of the U.S. triad, see, Dr. Dana J. Johnson, Dr. Christopher J. Bowie, and
Dr. Robert P. Haffa, Triad, Dyad, Monad? Shaping the U.S. Nuclear Force for the Future, Mitchell Institute for
Airpower Studies, Washington, D.C., November 2009.
106 For recent arguments in favor of a larger ICBM force see, Senate ICBM Coalition, The Long Pole of the Nuclear
Umbrella, A White Paper on the Criticality of the Intercontinental Balllistic Missile to the United States Security,
Washington, D.C., November 2009.
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Some argue that the United States should retain only the warheads on its Trident submarines. It
could convert its bombers to conventional missions and perhaps eliminate its land-based ICBMs.
However, the United States might also have to reduce the size of its Trident fleet, from the current
14 submarines to perhaps 8 or 10 submarines, if it reduced to 1,000 warheads. And, with so few
submarines, the United States might have to eliminate one of its submarine bases, leaving it with
submarines based only in the Atlantic or only in the Pacific Ocean. This change may not be
consistent with current submarine operations and employment plans. President Obama and the
U.S. military may want to consider the implications of these basing, operational, and policy
changes, before deciding whether or not to reduce to 1,000 warheads, as opposed to choosing the
warhead number first then deciding later how to base and operate the remaining nuclear forces.
Safety, Security, and Management Issues
In late August 2007, a B-52 bomber based in Minot, North Dakota, took off on flight to Barksdale
Air Force Base in Louisiana. The bomber carried 12 air-launched cruise missiles that were slated
for retirement at Barksdale. As a result of a series of errors and missteps in the process of
removing the missiles from storage and loading them on the bombers, six of the missiles carried
live nuclear warheads, instead of the dummy warheads that were installed on missiles heading for
retirement. This episode led to a series of studies and reviews by the Air Force that identified the
source of the episode and identified a number of steps the Air Force should take to improve its
handling of nuclear weapons.107
In early June 2008, Secretary of Defense Robert Gates requested the resignations of the Secretary
of the Air Force, Michael Wynne, and the Chief of Staff of the Air Force, General Michael
Mosely, from their positions, at least in part, due to concerns about that shortcomings in the Air
Force’s handling of nuclear weapons “resulted from an erosion of performance standards within
the involved commands and a lack of effective Air Force leadership oversight.”108 Secretary Gates
appointed a task force, lead by former Secretary of Defense and Energy James Schlesinger, to
provide “independent advice on the organizational, procedural and policy improvements
necessary to ensure that the highest levels of accountability and control are maintained in the
department’s stewardship of nuclear weapons, delivery vehicles, sensitive components and basing
procedures.”109
Several of the studies that reviewed this event have concluded that the Air Force leadership has
lost its focus on the nuclear mission as the Air Force has diverted resources to more pressing
missions related to the ongoing conflicts in Iraq and Afghanistan. As a result the “nuclear
enterprise” has been allowed to atrophy, with evident declines in morale, cohesion, and
capability.110 These reports suggest that the United States restore its focus on the nuclear mission
107 See, for example, The Defense Science Board Permanent Task Force on Nuclear Weapons Surety. Report on the
Unauthorized Movement of Nuclear Weapons. February 2008.
108 Nuclear Lapses Trigger Ouster of Top U.S. Air ForceOfficials. Global Security Newswire. June 6, 2008.
109 U.S. Department of Defense. Office of the Assistant Secretary of Defense (Public Affairs). Department of Defense
Announces Task Force on Nuclear Weapons Management. June 12, 2008.
110 See, for example, United States Air Force, Reinvigorating the Air Force Nuclear Enterprise, Prepared by the Air
Force Nuclear Task Force, Washington, D.C., October 24, 2008, http://www.af.mil/shared/media/document/AFD-
081024-073.pdf. See also, Report of the Secretary of Defense Task Force on DOD Nuclear Weapons Management (the
Schlesinger Commission), Phase I: The Air Force’s Nuclear Mission, Washington, D.C. September 2008.
http://www.defenselink.mil/pubs/Phase_I_Report_Sept_10.pdf
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and repair long-standing and often-identified deficiencies in manpower and training programs for
crews that maintain and service nuclear weapons and operate nuclear-capable bombers. The
studies have identified a number of organizational changes to achieve these goals. For example,
the Air Force has created a new Global Strike Command, based at Barksdale Air Force Base, that
is responsible for both the ICBM force and the nuclear-capable bombers. This organization began
its operations in early 2009. The Air Force has also established a new headquarters office in the
Pentagon that will monitor and manage the resources and policies dedicated to the nuclear
mission.
Others, however, take away a different lesson. Some have suggested that the evident weaknesses
in the Air Force’s procedures argue for removing nuclear weapons from the whole of the bomber
fleet.111 Congress may address concerns about these issues, and review possible changes in
command structures and security procedures, as it reviews nuclear weapons policies and
programs during its next session.
Author Contact Information
Amy F. Woolf
Specialist in Nuclear Weapons Policy
awoolf@crs.loc.gov, 7-2379
111 Kristensen, Hans. Nuclear Safety and the Saga of the Missing Bent Spear. Federation of the American Scientists.
February 22, 2008. http://www.fas.org/blog/ssp/2008/02/nuclear_safety_and_the_saga_ab.php
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