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Chapter 20


The mission of U.S. strategic nuclear forces is to deter aggression against the United States or its allies and to convince potential adversaries that initiating an attack would be futile. To do this, the United States must maintain survivable nuclear forces of sufficient size and capability to hold at risk a broad range of assets valued by potentially hostile foreign powers. The two basic requirements that guide U.S. planning for strategic nuclear forces are the need to provide an effective deterrent while conforming to treaty limitations, and the need to be able to reconstitute adequate additional forces in a timely manner if conditions require.

Russia currently possesses about 23,000 strategic and tactical nuclear weapons and will retain a sizable nuclear arsenal even with the ratification of Strategic Arms Reduction Treaty ( START) II. Furthermore, the political situation in Russia remains volatile and uncertain; a return to a foreign policy hostile to the United States is a possibility. Moreover, China is growing militarily and economically and has the potential to make major increases in the size and capability of its strategic nuclear arsenal in the near future. Hence, while the threat of a massive nuclear attack on the United States is lower than it was during the Cold War, there is still a valid need to maintain substantial strategic nuclear forces.


Until START II is ratified by Russia, the United States will protect options to maintain a strategic nuclear arsenal consisting of the following:

If START II is implemented, the arsenal will be modified by the year 2003 as follows:

Under START II, the combined total of accountable warheads cannot exceed 3,500 and the number of accountable warheads on SLBMs cannot exceed 1,750.

There has been a major reduction in the U.S. strategic nuclear arsenal in recent years. Table 29 compares the U.S. arsenals for FY 1990, FY 1997, and FY 2003. All force levels are for the end of the years in question.

Land-Based Intercontinental Ballistic Missiles

The United States has 530 Minuteman III ICBMs and 50 Peacekeeper missiles. The Minuteman III force will be reduced to 500 missiles by the end of FY 1998. If START II enters into force, the United States will modify these missiles to carry only one warhead each and will retire all Peacekeepers. As part of this transition, the Department may transfer the Mark 21 warhead from the Peacekeeper to the Minuteman force. Compared with earlier warheads, Mark 21s contain additional safety-enhancing features that reduce the risk of an accidental nuclear explosion and help prevent plutonium dispersal in the event of a fire.

The United States is not developing or producing any ICBMs, and has no current plans to develop a new ICBM. This makes it difficult to sustain the industrial base needed to maintain and modify strategic ballistic missiles. To help preserve key industrial technologies needed to sustain ICBMs and SLBMs, the Department is providing funding to preserve a core of expertise in the areas of reentry vehicle and guidance system technology.

Sea-Based Ballistic Missiles

SSBNs are the most survivable element of the strategic nuclear triad. A significant portion of the SSBN fleet is at sea at any given time, and all submarines that are not undergoing long-term maintenance can be deployed during a crisis. The U.S. SSBN fleet consists of 17 Ohio-class submarines. The final Ohio-class SSBN, the USS Louisiana, is scheduled to be commissioned in 1997. No new SSBNs or SLBMs are under development.
Table 29
Reductions in U.S. Strategic Nuclear Arsenal FY 1990, FY 1997, FY 2003
FY 2003
FY 1990
FY 1997
ICBMs 1,000 580 550 500
Declared Warheads on ICBMs 2,450 2,090 Not over 2,000 500
SLBMs 568a 432 432 336
Declared Warheads on SLBMs 4,864a 3,456 Not over 3,456 Not over 1,750
Ballistic Missile Submarines 31a 18 18 14
Declared Warheads on Ballistic Missiles 7,314a 5,546 Not over 4,900 Not over 2,250
Heavy Bombers (PMAI/TAI) 282/324b 102/202 60/92c 60/92c
NOTE: PMAI = primary mission aircraft inventory; TAI = total aircraft inventory.
a Excludes five decommissioned submarines (and their associated missiles and warheads) that were still START   accountable.
b Excludes FB-111s.
c Excludes 95 B-1s that will be devoted entirely to conventional missions.

The Trident II (D-5) missile has improved range, payload, and accuracy relative to all previous SLBMs; this increases both the survivability and the effectiveness of the SSBN fleet. The first eight Ohio-class submarines carry the Trident I (C-4) missile; the final ten have been or will be equipped, at the time of construction, with the newer D-5. The FY 1998 budget provides for continued procurement of D-5 missiles to support the conversion of SSBNs currently carrying C-4 SLBMs. The retrofits will be accomplished during regularly scheduled ship depot maintenance periods beginning in FY 2000. Under current plans, if START II enters into force, four submarines will be retired, leaving 14 SSBNs armed with D-5s. These missiles, while capable of carrying eight warheads, will be downloaded consistent with START II limits.

Long-Range Bombers

The U.S. bomber force currently consists of 95 B-1s (48 PMAI), 94 B-52s (44 PMAI), and 13 B-2s. With the growing number of B-2s and the improving conventional capability of the B-1, the Department plans to retire 23 of the 94 B-52s in FY 1998. The twenty-first, and last, of the programmed B-2s is scheduled to become operational in FY 2000. Although these 21 B-2s, in combination with other strategic assets, will meet all expected nuclear requirements, options to expand the B-2 fleet because of its conventional capabilities continue to be examined. In particular, the Department's ongoing Deep-Attack Weapons Mix Study is evaluating the cost-effectiveness of procuring additional B-2s.

All three types of U.S. bombers can deliver either nuclear or conventional weapons. By 1999, all B-1 bombers are expected to be dedicated exclusively to conventional missions. While these aircraft would not be available for nuclear missions on short notice, they could be returned to a nuclear role given sufficient time and a requirement to do so. The B-2 and B-52 forces, by contrast, will continue to have both nuclear and conventional missions.

Reflecting the increased emphasis on nonnuclear operations, bomber modernization efforts are focused primarily on improving conventional warfighting capabilities. For example, several new precision-guided weapons will be deployed on the bomber force between FY 1997 and FY 2003. The B-1 and B-2 will receive various upgrades to improve their performance in conventional missions. For details on these programs, see the Conventional Forces chapter.

Consistent with the post-Cold War drawdown in nuclear forces, programs to acquire new nuclear weapons for bombers have been terminated and the inventory of such weapons has shrunk. Short-range attack missiles ( SRAM) have been retired. The SRAM-II, a proposed replacement for the SRAM-A, was canceled several years ago. Procurement of the AGM-129 advanced cruise missile was halted at 460 in lieu of 1,460. Moreover, some AGM-86B air-launched cruise missiles ( ALCMs) have been converted to conventional air-launched cruise missiles (and redesignated AGM-86Cs) and some gravity bombs and ALCMs have been retired or placed in dormant storage. Some additional AGM-86Bs will be converted to AGM-86Cs in FY 1997.


Steps to ensure that the Minuteman III system can be maintained well into the next century are being taken. For example, installation of new guidance subsystems is scheduled to begin in FY 1998. Moreover, Minuteman III first-stage solid rocket motors will soon be overhauled to correct age-related degradation and to maintain system reliability. Similarly, the motors for the second and third stages of the rockets will be replaced beginning in FY 2001.

The bomber force is no longer maintained on constant alert, although it could be returned to alert status within a few days if necessary. This change in policy reduces stress on aircraft crews and allows greater emphasis to be placed on conventional training. By contrast, there has been no significant change in the alert status of U.S. ICBMs or SSBNs. For example, the United States maintains two full crews for each SSBN, and about two-thirds of all operational SSBNs are usually at sea. On average, about 10 percent of U.S. SSBNs are undergoing long-term overhauls at any given time, and thus are not immediately available for use. U.S. ICBMs are maintained on continuous alert, but no ICBMs or SLBMs are aimed at any country on a daily basis. This change in targeting policy enhances strategic stability and reflects the new relationship between the United States and Russia, while protecting against the consequences of an accidental launch. The missiles could, however, be returned to their previous targeting status on short notice.


Funding for strategic nuclear forces - bombers, ICBMs, and SLBMs - has declined in recent years. The fraction of the total defense budget that is devoted to nuclear forces also has declined. Moreover, one of the weapon systems included in this category - the B-1 - is in the early stages of its transition to a conventional role.

Modernization programs for strategic forces have been completed or curtailed during the past few years. The only major acquisition efforts that remain are deliveries of the final eight programmed B-2 bombers, B-2 modifications, B-1 conventional mission upgrades, Trident II missile procurement, and Minuteman III life extensions. With most nuclear modernization efforts having been completed, programs to sustain force readiness now account for most strategic nuclear funding.

The portion of the strategic budget devoted to operations and support has increased from about 40 percent of the total in 1991 to about 65 percent today and is projected to rise to 67 percent by 2003.


Strategic forces remain a critical element of the U.S. policy of deterrence. Although the forces have been reduced in the aftermath of the Cold War, and the percentage of the defense budget devoted to them has declined, strategic forces continue to provide a credible deterrent. Consequently, the United States will protect options to maintain its strategic capabilities at START I levels until the START II treaty has entered into force.

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