Although emphasis has shifted in the post-Cold War period from global, possibly nuclear, war to regional conflicts, strategic nuclear deterrence remains a key U.S. military priority. The mission of U.S. strategic nuclear forces is to deter attacks on the United States or its allies and to convince potential adversaries that seeking a nuclear advantage would be futile. To do this, the United States must maintain nuclear forces of sufficient size and capability to hold at risk a broad range of assets valued by potentially hostile foreign nations. The two basic requirements that guide U.S. planning for strategic nuclear forces therefore are: the need to provide an effective deterrent while conforming to treaty-imposed arms limitations, and the need to be able to reconstitute adequate additional forces in a timely manner if conditions require.
The threat of a massive nuclear attack on the United States is much lower than it was during the Cold War. Still, about 25,000 nuclear weapons remain in Russia and on the territories of two other former Soviet republics. Even under the START II treaty, which has yet to be ratified by the Russian government, Russia will retain a sizable nuclear arsenal. In addition, the future political situation in Russia remains volatile and uncertain; a return to authoritarian rule or to a foreign policy hostile to the United States are both possibilities. 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 during the next decade. Finally, the risk of nuclear proliferation is higher than in the past. Several countries are attempting to acquire technology for building nuclear weapons, nuclear-capable missiles, or both. In fact, there have been several unsuccessful attempts to smuggle nuclear materials from the former Soviet Union. Therefore, the risk exists that one or more potentially hostile countries could, over the next decade, acquire a limited capability for the long-range delivery of nuclear weapons.
FORCE STRUCTURE AND CAPABILITIES
Assuming START II is implemented by the year 2003, the planned U.S. strategic nuclear arsenal would include the following:
By the year 2003, the entire force of B-1 bombers is expected to be dedicated exclusively to conventional missions. While these aircraft would thus 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 be assigned both nuclear and conventional missions.
There has been a major reduction in the U.S. strategic nuclear arsenal in recent years, and this downward trend is expected to continue for several more years. Table IV-18 compares actual or projected U.S. nuclear forces in FY 1989, FY 1996, and FY 2003. All force levels are for the end of the fiscal years in question, and the numbers for FY 2003 are based on the assumption START II will be implemented by that time. The table focuses exclusively on strategic nuclear weapons. The United States also had a sizable arsenal of tactical nuclear weapons in FY 1989; most of those weapons have since been withdrawn from deployment, and many are being eliminated.
Land-Based Intercontinental Ballistic Missiles
The U.S. land-based ICBM force consists of 530 Minuteman III ICBMs capable of carrying three warheads apiece and 50 Peacekeeper missiles, each deploying 10 warheads. As part of the ongoing drawdown, the Minuteman III force will be reduced to 500 missiles by the end of FY 1998. Assuming START II enters into force, the United States will modify these missiles to carry only one warhead each and will eliminate the Peacekeeper system by the year 2003.
The Defense Department is preserving the option to transfer Mark 21 warheads from the Peacekeeper to the Minuteman system. The Mark 21 was identified as the safest U.S. nuclear warhead by the Drell Commission, established by Congress to investigate potential hazards associated with handling, transporting, and deploying U.S. nuclear warheads. Mark 21 warheads contain several safety-enhancing features designed to reduce the risk of an accidental nuclear explosion and prevent molten plutonium from leaking outside the warhead in the event of a fire.
|Reductions in U.S. Strategic Forces, FY 1989 Through FY 2003|
|FY 1989||FY 1996||FY 2003 [a]|
|SLBM Warheads||4,992||Over 3,000||Approx. 1,750|
|Heavy Bombers (PMAI/TAI)||324/359||101/173||130/181[c]|
|NOTE: PMAI = Primary Mission Aircraft Inventory TAI = Total Aircraft Inventory|
[a] Assumes START II entry into force.
A significant challenge in future planning will be to ensure the continued viability of the industrial base needed to maintain and modify deployed strategic ballistic missiles. For the first time in many years, the United States is not developing or producing any land-based ballistic missiles. Furthermore, development of a new ICBM is not anticipated for at least 15 years. The Department is exploring new ways to preserve key industrial technologies; reentry vehicle and guidance technologies are particularly problematic, given the lack of commercial applications. The FY 1997 budget provides funding to preserve a core of reentry vehicle expertise and the capability to manufacture specialized materials. There is a similar effort in the area of guidance system technology; the support provided will assist the United States in maintaining an industrial capability to address guidance system problems and design prototype systems.
Sea-Based Ballistic Missiles
Nuclear-powered ballistic-missile submarines (SSBNs) armed with long-range SLBMs will assume a greater share of the strategic nuclear deterrence mission if START II is implemented. Under START II, the SLBM force will provide about half of the 3,000 to 3,500 nuclear warheads the United States will be permitted to deploy. SSBNs, which are very hard to detect when at sea, 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 not in the shipyard for long-term maintenance can be deployed during a crisis.
The U.S. SSBN fleet currently consists of 16 Ohio-class submarines. Two additional Ohio-class SSBNs, now under construction, will be commissioned in 1996 and 1997, respectively. The final Ohio-class submarine, SSBN 743 (USS Louisiana), is scheduled to be commissioned in August 1997 and to make its first operational patrol in FY 1998. No new SSBNs or SLBMs are currently under development.
The Trident II (D-5) missile, offers improved range, payload, and accuracy over the Trident I (C-4) and all previous SLBMs. This advanced weapon allows the SSBN force to hold at risk, with increased survivability, almost the entire spectrum of strategic targets of any adversary. The first eight Ohio-class submarines carry the C-4 missile; the final 10 have been or will be equipped, at the time of construction, with the newer D-5. The FY 1997 budget provides for continued procurement of D-5 missiles to support a 14-submarine D-5 SSBN force. Four of the eight submarines currently equipped with the C-4 missile will be retrofitted with the D-5 during regularly scheduled ship maintenance periods. Under current plans, following START II's entry into force, the other four SSBNs will either be converted into special-purpose submarines or be retired. This will leave a total force of 14 ballistic-missile submarines, all armed with D-5s. The D-5 missiles, while capable of carrying eight warheads, will be downloaded consistent with START II limits. A recent study, done at Congress's request, affirmed that converting to an all-D-5 SSBN force will provide operational and economic advantages over maintaining a force in which some SSBNs are equipped with the older C-4 missile. The Ohio-class submarine force will form the bulk of the U.S. nuclear deterrent for the indefinite future. The defense budget therefore continues to invest, albeit at a reduced rate, in measures to enhance SSBN security and survivability.
At the end of 1995, the U.S. long-range bomber force included 95 B-1s (48 PMAI), 94 B-52s (62 PMAI), and eight B-2s (six PMAI). Under current plans, the Air Force will receive its twentieth, and last, operational B-2 in FY 2000.
In the past, the bomber force was oriented primarily toward nuclear missions. However, given the growing emphasis on conventional warfare and the fact that all nuclear weapons acquisition and integration programs associated with the START II bomber force are now complete, current modernization efforts are aimed primarily at improving conventional bombing capabilities. Programs in this area will be guided by the recently completed Heavy Bomber Force Study and the ongoing Deep Attack/Weapons Mix Study, both of which are discussed in the Aviation Forces chapter of this report.
All three types of bombers currently in the force can deliver either nuclear or conventional weapons. Under START II, B-1 bombers will no longer be counted as nuclear weapon carriers once the United States notifies Russia that these aircraft have been reoriented to an exclusively conventional role. By contrast, B-52s and B-2s will retain nuclear capabilities. For example, a B-2 can carry up to 16 gravity bombs and a B-52 can carry up to 20 long-range cruise missiles for nuclear missions. Under the terms of the START II agreement, conventional bombers must be based separately from bombers with nuclear roles, and they may not participate in exercises or training for nuclear missions.
Finally, reductions have been made in the inventory of nuclear weapons for bombers, and weapons development programs have been terminated. Short-range attack missiles (SRAM-As), whose warheads lacked many of the desirable safety features of newer warheads, 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 missiles in lieu of the originally planned 1,460. Moreover, some AGM-86B 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 1996 and 1997.
READINESS AND SUSTAINABILITY
Plans to ensure that the Minuteman III system can be maintained at least to the year 2010 are well under way. The Rockwell International Corporation was selected in 1993 to replace aging and potentially unreliable components in the Minuteman guidance system. Installation of new guidance subsystems is scheduled to begin in FY 1998. Minuteman III solid rocket motors will be overhauled to correct age-related degradation and to maintain system reliability. The first-stage motors will go through their first depot refurbishments after having been deployed for more than 25 years. The motors for the second and third stages of the rockets, which have only about a 17-year service life, will be replaced with a refurbished second stage and a remanufactured third stage. Installation of these motors will begin in FY 2001.
Reflecting the relaxation in Cold War tensions, the bomber force is no longer maintained on constant alert. This change in policy reduces stress on the aircraft and crews and allows a greater emphasis on conventional training. Although U.S. bombers are no longer kept on 24-hour alert, they could be returned to that status within a few days if circumstances warranted.
Whereas the bomber force is now on a much lower state of alert than it was during the Cold War, there has been no significant change in the alert status of U.S. ICBMs or SSBNs. For example, the United States still maintains two full crews for each SSBN, and about two-thirds of all operational SSBNs are at sea at any given time. (On average, about 10 percent of the submarines in the SSBN force are undergoing long-term overhauls at any point in time, and thus are not immediately available for deployment.) U.S. ICBMs are still maintained on continuous alert, but no ICBMs or SLBMs are aimed at any country on a day-to-day basis. This change in targeting policy enhances strategic stability and reflects the new relationship between the United States and Russia, while protecting against the remote possibility of an accidental launch. The missiles could, however, be returned to their previous targeting status on short notice.
FUNDING AND MODERNIZATION
Reflecting the end of the Cold War, funding for strategic nuclear forces -- bombers, ICBMs, and SLBMs -- has fallen and is now at its lowest level in more than 30 years. As the following charts show, this is true in terms of both total expenditures and the fraction of the total defense budget that is devoted to nuclear forces. Moreover, one major nuclear system -- the B-1 bomber -- is in the early stages of its transition to a conventional role.
Modernization programs for strategic forces were either completed or severely curtailed during the past few years. The only major acquisition efforts that remain are modifications of B-2 bombers to the Block 30 standard, B-1 conventional mission upgrades, Trident II (D-5) missile procurement, and Minuteman III life extensions. Moreover, two of these programs are designed to enhance performance in conventional, as opposed to strategic nuclear, roles. As the chart at the bottom of the preceding page shows, expenditures to sustain the readiness of U.S. nuclear forces now account for most strategic nuclear funding, having increased from about 40 percent of the total in FY 1991 to about 62 percent today. As the force structure stabilizes and modernization programs are concluded, operations expenditures will continue to dominate the decreasing strategic nuclear forces budget.
Strategic forces remain a critical element of the U.S. policy of deterrence. Although these forces are being reduced in the aftermath of the Cold War, and the percentage of the defense budget devoted to them is declining, strategic forces will continue to provide a strong and credible deterrent to nuclear attack. Moreover, the United States will protect options to maintain its strategic capabilities at START I levels until the START II treaty has entered into force.