A Regime of Progressive Constraints
The program recommended in this chapter would shift the focus of U.S. nuclear policy. Nuclear forces would be reduced; their roles would be more narrowly defined; and, while preserving the core function of deterring nuclear aggression, increased emphasis would be placed on achieving higher standards of operational safety. This shift would entail:
further reductions in active weapons inventories;
including all nuclear warheads in arms reductions;
arrangements for exact, verified accounting and assured physical security of all warheads and fissionable materials;
transforming the operational practices of active forces to eliminate continuous-alert procedures, commitments to rapid retaliation, and mass attack targeting; and
reaffirming the integral relationship between restrictions on offensive and defensive systems.
As they make progress, the United States and Russia will want to engage China, France, and the United Kingdom on these issues and eventually make them full partners in the nuclear reductions process. And the regime of global nonproliferation agreements, including comprehensive new controls on fissile materials, will need to be cemented and expanded.
Taken together, these measures would transform nuclear force structure and operations as well as the ways that nations view the roles that nuclear weapons play in their national security policies. As agreed at the Helsinki summit, the United States and Russia should conclude an agreement to reduce to about 2,000 deployed strategic warheads each in a START (Strategic Arms Reduction Treaty)
III negotiation. Although important, this is only a first step. Efforts to begin transforming U.S. and Russian nuclear operations also should begin and need not await agreement on further force reductions. There are certainly links between reductions and changes in operations, but progress in one is not dependent on progress in the other. There should also be considerable flexibility in the transition from one stage of reductions to another, and the possibility of eliminating the dividing lines between stages should not be excluded. The committee has prescribed no time period in which each or all of the stages should be completed, since decisions on these matters depend on specific political and technological choices that cannot be foreseen now. The most important point is that the overall process should be structured to make it possible to proceed expeditiously to significantly lower levels of nuclear weapons, with dramatic changes in nuclear operations well in train.
A continuing high-priority effort is also needed to improve the protection of nuclear weapons and fissile materials in Russia. Joint U.S.-Russian work along these lines, which has been going on since 1991 under the Nunn-Lugar Cooperative Threat Reduction Program, complements and strengthens arms reductions and other changes in nuclear policies. (Because this committee and other NRC committees have recently offered detailed analysis and recommendations on this subject in other reports, the issue is not treated in detail here.)1
AN IMMEDIATE STEP: TO 2,000 DEPLOYED STRATEGIC WARHEADS
At their March 1997 summit, Presidents Clinton and Yeltsin agreed that the next step after START II, with its level of 3,000 to 3,500 deployed strategic warheads, enters into force should be negotiation of a follow-on START III agreement reducing the number of deployed strategic warheads to 2,000 to 2,500 on each side. The committee believes that serious discussions of START III should begin immediately as part of the effort to encourage the Russian Duma's ratification of START II and also to reduce the Duma's current leverage over the arms control process. Formal negotiations were begun on START II and in that case led to a successful conclusion even though final ratification of START I had not been completed.
To move as quickly as possible to this reduced ceiling, the new agreements should operate within the existing technical frameworks of START I and START II. This will necessitate deferring for a brief time the introduction of certain key concepts that are critical to still deeper reductions, such as including all nondeployed and nonstrategic nuclear warheads in the overall verification and accountability of nuclear warheads. Reductions to the 2,000 level should be easily accommodated within the existing and anticipated strategic force structures of both sides without creating any operational or survivability problems and would more than adequately fulfill the core deterrent function for both sides.
President Yeltsin originally proposed a level of 2,000 at the beginning of the START II negotiations, but the United States concluded it was too large a step to take initially. As discussed in Chapter 2, a majority in the Russian Duma currently opposes ratification of START II. Now that Presidents Clinton and Yeltsin have agreed on a framework for a START III treaty, the impasse in the Duma could be resolved to the mutual advantage of both countries.
The committee expects that in START III both the United States and Russia will maintain ballistic missile submarines as the major component of a smaller number of nuclear delivery systems. Of the U.S. nuclear delivery systems that would remain under START II, ballistic missile submarines are the most survivable. They have proven to be dependable, are mobile, and can be concealed for long periods. They can roam the oceans of the world with little constraint and can remain at sea for an extended time. If the United States deployed half of a force of 2,000 warheads on submarines, and continued the current practice of having two-thirds of its submarines at sea, about 650 warheads would survive an attack, even if all bombers, land-based intercontinental ballistic missiles (ICBMs), and submarines in port were destroyed. Given the same reasoning, it can be assumed that Russia would continue to deploy a significant portion of its 2,000 warheads in a survivable mode.
In anticipation of the time when reductions to very low levels might take place, it would be useful at this stage to begin to involve the United Kingdom, France, and China. Their involvement, however, should probably be limited to informal exchanges in which the United States and Russia would keep the other nuclear powers informed of their progress. In turn, these states would have the opportunity to express their views. These exchanges will become more important when negotiations expand in the next step to include all strategic and nonstrategic warheads.
The remainder of this chapter offers prescriptions to resolve the questions raised in Chapter 2. These include recommendations (1) transforming further the U.S.-Russian relationship to increase operational safety and to make further nuclear arms reductions comprehensive; (2) strengthening the nonproliferation regime to provide reassurance to nonnuclear states and to respond to further proliferation should it occur; and (3) making much deeper reductions in the numbers of nuclear weapons.
FURTHER TRANSFORMATION OF THE U.S.-RUSSIAN INTERACTION
Limiting All Nuclear Warheads
The need to shift arms control from its focus on delivery vehicles to include limits on warheads, acknowledging the verification challenge this raises, was noted previously. All nuclear warheads—regardless of type, function, stage of assembly, associated delivery vehicle, or basing mode—should be counted.
Limits on the total inventory of nuclear warheads would minimize the reversibility of reductions and diminish the possibility of rapid breakout. Such limits would force the eventual dismantling of thousands of additional warheads, improve the stability of the nuclear balance, and demonstrate the commitment of the United States and Russia to very deep reductions.
Verifying limits on nondeployed and nonstrategic warheads would require transparency measures regarding the storage, production, and dismantling of nuclear warheads, as well as a mechanism for exchanging and verifying information about the location and status of warheads. These measures would go beyond those required to verify the limits on delivery vehicles and launchers in START I and II. In September 1994, Presidents Clinton and Yeltsin took the first step in this direction when they agreed in principle to exchange data on their nuclear arsenals and instructed their experts to meet to discuss what information could be provided to the other side. Efforts to implement these measures, and the transparency measures associated with the end of Russian weapons plutonium production were at an impasse as this study was coming to a close, so developing U.S.-Russian cooperation is still a formidable challenge. But it is apparent that once such cooperation is realized, the following information should be included:
the current location, type, and status of all nuclear explosive devices and the history of every nuclear explosive device manufactured, including the dates of assembly and dismantling or destruction in explosive tests;
a description of facilities at which nuclear explosives have been designed, assembled, tested, stored, deployed, maintained, and dismantled, and which produced or fabricated key weapon components and nuclear materials; and
the relevant operating records of these facilities.
An exchange of this sort would be a valuable confidence-building measure even in the absence of a formal limit on warhead numbers, but the real value of a data exchange lies in its contribution to verifying such limits. Perhaps the simplest way to verify the data exchange would be to conduct both scheduled and unannounced inspections of nuclear weapons storage sites. Such inspections could begin with warheads slated for dismantling, move to warheads in the inactive reserve, and finally bring into the process weapons in the active stockpile (such as nonstrategic and bomber weapons in storage bunkers). Inspectors could verify the number of warheads at a declared site using relatively simple radiation detection equipment.
Even without a comprehensive and continuous warhead monitoring arrangement requiring full collaboration, inspectors with occasional access to declared facilities could verify the number of warheads present. Evolving technology will provide some improvement in the unilateral detection and surveillance of undeclared enrichment and reprocessing sites as well.2 As a practical matter, all forms of agreed surveillance, from existing methods to the most advanced new
technologies, would have to protect the secrecy of nuclear weapons design information, but this requirement can be met without undermining the legitimate purposes of transparency.
One particularly important focus of such an inspection process would be to verify that warheads removed from the declared stockpile for dismantling have indeed been destroyed and not simply moved to a hidden storage facility. In an earlier report, this committee described a straightforward verification scheme to achieve this goal, using perimeter-portal monitoring at dismantling facilities.3 This scheme would count warheads as they entered the dismantling facility and would count "pits" (the basic nuclear component of warheads) as they exited, using intrinsic radiation or radiographic techniques. The pits would be stored under safeguards, initially bilateral, to ensure that they are not incorporated into new nuclear weapons, pending the ultimate disposition of the material.
Taken together, over time these measures could substantially increase U.S. and Russian confidence that remaining nuclear warheads and materials were accounted for. But no verification system could provide complete assurance that no clandestine stocks remained. Therefore, as nuclear reductions proceed to lower levels, the issue of how much uncertainty is acceptable becomes increasingly important. This, in turn, places a greater burden on the international security system to give confidence that there will be few incentives to cheat or that violations, when detected, will be dealt with swiftly.
Eliminating the Hair Trigger
In assessing the risks associated with nuclear arsenals, the operational and technical readiness of nuclear weapons for use is at least as important as the number of delivery vehicles or warheads. Elimination of continuous-alert practices should be pursued as a principal goal in parallel with, but not linked to, START III. It would reduce the perceived danger of short-warning-time attacks; it would make detecting preparations to use nuclear weapons easier and thereby increase the time available for political solutions; it would reduce pressures on command-and-control systems to stand ready to respond quickly and thus would decrease the chance of erroneous launch of nuclear weapons or a launch in response to a spurious or incorrectly interpreted indication of impending attack; it would allow both sides to increase barriers to unauthorized use of nuclear weapons; and it would enhance the political relationship by eliminating the assumption that the other side might launch a surprise attack.
Ideally, the launch readiness of nuclear forces would be reduced in ways that are readily transparent to the other side, so that both sides can be assured that a large-scale surprise attack is not possible. Care must be taken, however, to reduce launch readiness in ways that do not lead to instability. This requires that a portion of the force sufficient to satisfy the core function be able to survive any plausible attack. In addition, both sides must be convinced that neither could
obtain a decisive advantage over the other by suddenly rushing to ready additional forces for use.
Reducing and eventually eliminating the possibility of surprise attack in a transparent and stabilizing fashion are a challenging but achievable goal. A small survivable force sufficient to satisfy the core function can be deployed on submarines at sea or mobile missiles out of garrison. Although this force need not—and should not—be operationally capable of rapid use, it might be difficult, at least in the near term, to demonstrate to the other side that these forces are incapable of prompt launch without compromising their survivability. However, the remainder of the force—silo-based missiles, mobile missiles in garrison, missiles on in-port submarines, and strategic bombers—can and should be rendered incapable of rapid launch in ways that would be readily verifiable. This has already been accomplished for bombers, by removing the nuclear bombs and air-launched cruise missiles and placing them in storage bunkers. In the case of ballistic missiles it is possible to remove warheads, shrouds, guidance systems, or other key components. Inspectors or remote monitoring devices could then verify that the systems had not been readied for launch and provide timely warning of any attempt to do so. A number of possibilities exist along these lines, and the defense establishments of the nuclear weapons states should be directed to develop a range of acceptable options as part of the reductions process.
Over the longer term, the United States and Russia, together with the other nuclear powers, should search for ways to assure each other than all nuclear weapons, including those on submarines at sea or on mobile missiles out of garrison, are incapable of being used quickly and without warning. The committee believes that it is possible to develop ways to do this while preserving stability and survivability. Although a number of means have been suggested for achieving this result (e.g., by having submarines patrol out of range of potential targets), this is an issue that requires detailed further study.
As a related confidence-building measure, the United States and Russia should adopt cooperative practices to assure each other that neither is preparing to launch a nuclear attack. Today, verification of alert status and warning of attack are provided solely by national technical means such as photo-reconnaissance, attack-warning satellites, and early-warning radars. All five nuclear weapons states could gain from an evolving program to share such intelligence with each other, or to install sensors (video cameras, seismic sensors, and the like) near the nuclear forces of other states to verify their status. A program to exchange military officers would also enhance confidence over time in the low alert rate and benign intentions of the other side.
Revising Targeting Policy and War Planning
The committee noted in the previous chapter that it makes little sense to preserve targeting plans that were developed to deter the Soviet Union, an adversary
that no longer exists and whose successor state is in the process of dramatic change. The core deterrent function could be credibly maintained—and operational safety enhanced—while moving away from the concept of immediate overwhelming target destruction that dominated U.S. nuclear planning during the Cold War. In its aftermath, planning to retaliate massively against either military or civilian targets is not the appropriate basis for responsible decision making regarding the actual use or threat of use of nuclear weapons.
The United States should adopt a strategy that is based on much more selective target options and that would not require prompt attacks on counterforce targets or imperil major fractions of the nation's population either within or beyond the boundaries of the target area. Target planning might focus on major military facilities or core infrastructure such as energy network nodes located outside large urban areas, designed in all cases to minimize civilian casualties to limit the pressure for escalation and to allow political leaders to negotiate an end to nuclear attacks.
For decades U.S. nuclear war planning has focused on the articulation of a highly complex plan for nuclear war—the Single Integrated Operational Plan (SIOP). One original purpose of the SIOP—to integrate the target planning of the different U.S. armed services—remains valid. The SIOP contains thousands of targets and strictly prescribes U.S. nuclear operations through the various stages of a nuclear war. It incorporates many options, but its implementation is relatively inflexible. Now that the United States no longer faces a single, massive enemy with huge nuclear and conventional forces, the revolution in computation and communications makes possible a much more flexible strategy.
The committee concludes that U.S. national security would benefit from replacing the traditional SIOP concept with a much more flexible planning system of "adaptive targeting." Under this concept, U.S. military planners would retain and update lists of targets in potentially hostile nations with access to nuclear weapons. They would do so, however, under the presumption that nuclear weapons, if they were ever to be used, would be employed against targets that would be designated in response to immediate circumstances—and in the smallest numbers possible. Advance military planning and timely exercises are prudent and essential if national leaders are to have confidence in the dependability of their nuclear forces in a crisis. But there is a wide gulf between adaptive targeting and the present situation. Some changes in this direction have begun at the U.S. Strategic Command, but the move to an adaptive targeting approach should be accelerated and formally adopted.
Adaptive targeting would represent a natural complement to efforts to reduce the size and alert status of nuclear forces. The SIOP was constructed to coordinate a rapid attack by thousands of warheads against a well-defined enemy. As the size and alert status of nuclear forces change, and the probability of a massive Russian attack continues to fade, the United States will no longer require standing plans for a massive U.S. response. A dialogue between U.S.
and Russian military leaders on this subject would be useful and could help pave the way toward greater mutual understanding, which would facilitate deeper reductions in nuclear forces.
Relating Reductions and Ballistic Missile Defenses
A strong linkage exists between reductions in offensive forces and limits on defenses. This linkage was captured in the preamble to the Anti-Ballistic Missile (ABM) Treaty, in which the United States and the Soviet Union agreed that:
Effective measures to limit anti-ballistic missile systems would be a substantial factor in curbing the race in strategic offensive arms and would lead to a decrease in the risk of outbreak of war involving nuclear weapons [and] … would contribute to the creation of more favorable conditions for further negotiations on limiting strategic arms."4
The committee has already noted that plans to develop and deploy systems intended to provide or capable of providing even limited national missile defense could weaken and possibly destroy the value of the ABM treaty. This would, in turn, threaten the deeper reductions in offensive nuclear arms that the committee recommends. The committee concludes, therefore, that the ABM treaty must remain "a cornerstone of strategic stability," as it was described by Presidents Clinton and Yeltsin at the conclusion of the Helsinki summit.5 The ABM treaty is by no means a relic of Cold War thinking as some assert. On the contrary, it remains a logical adjunct of the continuing reality of offense dominance in conflicts involving nuclear weapons.
In a world in which the number of offensive nuclear arms is reduced drastically and the role of nuclear weapons is diminished, the ABM treaty will continue to play a crucial role. Opportunities to maintain and enhance its integrity will require periodic evaluation. Various technical constraints on tactical and national missile defense systems, always preserving the legitimate defensive capabilities against shorter-range missiles, can be consistent with the provisions of the treaty. For example, limits on the speed of interceptors or test warheads, intercept altitude, the number and geographical distribution of interceptors, sensor technology and integration, and the sale of technology to third parties should be investigated, and agreed interpretations should be negotiated in the Standing Consultative Commission.
Current U.S. counterproliferation policy puts great emphasis on the need for enhanced defenses against theater missiles. Some level of ballistic missile defense, in appropriate balance with other defensive measures, is desirable to defend U.S. forces and allies overseas from theater ballistic missiles. The focus of this activity should be to have available in the near future a mobile system capable of defending relatively small areas against projected theater ballistic missile threats, which the committee believes will be limited to the 1,000 kilometer range for some time.
NUCLEAR REDUCTIONS AND NONPROLIFERATION
This section examines several issues that involve interests and factors beyond the direct control of the United States and Russia. Some have been addressed in detail in the past but will need strengthening in an era of very small numbers of nuclear weapons. Others have been identified before but not thoroughly addressed; in any case they need to be revisited now in the new international circumstances. All of these issues can and should be addressed in ways that both enhance international security in the short term and support evolution toward a future world order in which security does not depend on the maintenance of national nuclear arsenals and explicit or implicit threats to use them.
Engaging the Undeclared Nuclear States
Nuclear weapons presumably held by the undeclared nuclear states—India, Israel, and Pakistan—pose a vexing problem. Their possession of nuclear weapons would become an even more troubling issue when the United States and Russia consider reductions to very low levels of warheads. Ways must be found to engage the undeclared states in a manner that would make it advantageous for them to move toward nuclear disarmament. Engagement in the process should not encourage, much less require, these states to declare their nuclear status, however, since this would likely be counterproductive. There are at least two major risks with open acknowledgment of the undeclared nuclear arsenals. The first is that such declarations could be destabilizing if there were to be a lag between the announcement and elimination. However widespread the belief in the undeclared nuclear capability might be, there could be political repercussions, such as calls for punishment or compensating measures by adversaries in the region, once the suspicions were publicly confirmed. The second is that open acknowledgment could run the risk of appearing to confer legitimacy or rewards, thus decreasing the nonproliferation benefit.
Reductions in U.S. and Russian nuclear arsenals and global nonproliferation initiatives, though helpful, will not suffice to engage the undeclared states. In the case of South Africa—the only country that has destroyed its entire nuclear arsenal—changes in the regional security environment (the withdrawal of Soviet-sponsored troops from neighboring states) and in domestic politics (the transition to majority rule) convinced the leaders of South Africa that its security was better served without nuclear weapons than with them. Achieving a similar result for the three remaining undeclared nuclear states will require a similar stabilization of their political, security, and perhaps economic situations. Over the long term, progress along these dimensions probably will be more important than the pursuit of initiatives related directly to constraining or eliminating the nuclear weapons programs of these countries.
Patient but persistent diplomatic strategies that are tailored to the security
perceptions of each state will be required. Israel, for example, has already stated its willingness to enter into a nuclear weapon free zone (NWFZ) agreement provided that a comprehensive peace agreement for the Middle East is achieved.6 The greatest contribution that the United States can make to promoting Israeli nuclear disarmament is to expedite the peace negotiations and to ensure that, at an appropriate point, these negotiations are linked with negotiations on an NWFZ. In the meantime, the United States should encourage full Israeli participation in global nonproliferation initiatives, such as the Comprehensive Test Ban Treaty and a fissile material production cutoff.
The cases of India and Pakistan are more complex in that their nuclear weapons programs are linked to each other and to that of China. It seems highly unlikely that India would agree to join the NPT while China's nuclear arsenal remains unconstrained by arms control. Long-standing Indian policy suggests that its ratification of the NPT would likely require a commitment by China to reduce and eventually eliminate its arsenal, as well as requiring additional improvements in Sino-Indian relations. The more difficult case is that of Pakistan, which has a history of armed conflict with India and whose conventional forces are numerically inferior to those of India. In addition to other initiatives to improve the regional security environment, prospects for South Asian nuclear disarmament could be enhanced by conventional arms control and confidence-building measures protective of Pakistani security.
This is a long-term challenge, and the United States should take the lead in attempting to stimulate the negotiations that might lead to more durable stability in South Asia. In addition, the United States should focus on nearer-term measures designed to reduce the chances for an expanded nuclear arms race or the use of nuclear weapons on the subcontinent. This would include regional agreements not to deploy, use, or threaten to use nuclear weapons or nuclear-capable ballistic missiles, together with continued efforts to engage India and Pakistan in global initiatives, including the CTBT and a fissile material production cutoff, as well as international controls on the civilian production and use of fissile materials.
Strengthening the Nonproliferation Regime
As noted in the previous chapter, Article VI of the NPT commits the signatories to work in good faith toward nuclear disarmament.7 Achieving nuclear disarmament would require an international political order in which the possession of nuclear weapons would no longer be seen as legitimate or necessary to the preservation of national security, as discussed at greater length in Chapter 4. While building such an international order is very much a long-term project, a necessary even though not sufficient condition for its success will certainly be a continuing effort by the nuclear weapons states to reduce, systematically and progressively, the sizes of their nuclear arsenals and the roles that these play in their national security policies.
There are also important shorter-term links between arms reduction efforts by the nuclear weapons states and the prospects for nonproliferation. Perhaps most important, the short-term and medium-term effectiveness of the global nonproliferation regime requires the full support and cooperation of a large number of nonnuclear weapons states in the maintenance of a vigorous International Atomic Energy Agency with the inspection powers and resources required to do its job, the implementation of effective controls on the transfer of sensitive technologies, and the creation of transparency conditions conducive to building confidence that proliferation is not taking place. The degree of commitment of the nonnuclear weapons states to these crucial collective efforts can hardly fail to be affected by impressions about whether the weapons states are working seriously on the arms reduction part of the global nonproliferation bargain.
Some downplay the importance of nuclear weapons state arms reduction performance for nonproliferation by pointing to the many nonproliferation accomplishments that have been achieved without deep reductions by the nuclear weapons states, such as the termination of the nuclear-weapon programs of Argentina and Brazil, the relinquishing of nuclear weapons status by South Africa and three of the former Soviet republics, and the indefinite extension of the NPT in 1995. The committee believes this view does not give adequate consideration to the longer-term factors affecting this issues. Not only does it underrate the importance of the nuclear weapons states' performance for maintaining the active commitment to the nonproliferation regime of the large number of states that are not potential proliferants; it also fails to appreciate that none of the indicated nonproliferation victories is necessarily permanent, that the governments of many threshold states contain antibomb factions whose clout is strengthened or weakened by the actions of the nuclear weapons states, and that, most important, the world's expectations about what constitutes acceptable nuclear arms control performance by weapons states after the Cold War are likely to be different than they were when the Cold War was under way.
On this last point, while many members of the community of nations were probably not pleased with the immense nuclear arsenals accumulated by the United States and Russia during the Cold War, most understood that the characteristics of that deeply hostile and far-reaching confrontation constrained what could be expected from the two countries in the way of reductions in the sizes of those arsenals and the missions assigned to them. With the Cold War over, the world is likely to be impatient with U.S. and Russian maintenance of nuclear forces much more potent than the new circumstances seem to require. While the required majority for indefinite extension of the NPT was probably always assured, the essential consensus was only achieved by a combination of great diplomatic skill by the conference chair, the application of the immense political clout of the United States, and, crucially, a clear expectation of renewed commitment by the nuclear weapons states to faster, deeper, broader progress in nuclear arms limitations.
In addition to the reduction and dealerting steps discussed previously, three initiatives of the nuclear weapons states stand out as especially important in this regard: (1) achieving entry into force of the Comprehensive Test Ban; (2) extending NWFZs; and (3) expanding controls over fissile materials. All three would benefit the nonproliferation regime, as well as U.S. national security, in tangible as well as symbolic ways.
The Comprehensive Test Ban Treaty. Completing the text of the CTBT and opening it for signature represents a major nonproliferation achievement. Although the treaty cannot enter into force without the adherence of India, which is now adamantly opposed, the signatories (which include all of the nuclear weapons states) will be bound by customary international law not to violate the treaty's purpose. The overwhelming support the treaty received in the United Nations General Assembly in September 1996 and a growing number of signatories will create a powerful norm, which may well mean that there will never be another nuclear weapons test or other nuclear explosion. Moreover, with sufficient political will, the barrier against entry into force can be overcome, either by persuading India to sign or by relaxing the rigid entry-into-force requirement, which was included at the insistence of China, Russia, and the United Kingdom.
Controlling Proliferation Through NWFZs. Today, NWFZ agreements do not cover the regions with the greatest risks of nuclear threat, use, or proliferation—South Asia, Northeast Asia, and the Middle East. The effectiveness of such arrangements clearly depends on the participation of the states of greatest concern in the region; for example, Israel's participation would be essential for a successful agreement in the Middle East. But even partial agreements, as the Latin American NWFZ was for a long time, provide ways for states to take positive actions. In addition, they provide a regime in waiting for the day when conditions improve. The United States should support these agreements by signing the relevant treaty protocols promptly and without reservations.
A new NWFZ in Central Europe, perhaps including western states of the former Soviet Union, would offer immediate security advantages to Russia as well as NATO and states of the former Warsaw Pact. It could make accession to NATO by new states from the region more acceptable to Russia. At the same time, some former Warsaw Pact states and Soviet republics are seeking security assurances and guarantees that their nonnuclear status will not make them vulnerable to coercion or, in the worst case, aggression. A formal Central European NWFZ, coupled with negative security assurances from the nuclear weapons states, would help relieve these pressures and provide another basis for developing cooperative security arrangements in a region that for centuries has been subjected to innumerable invasions, occupations, and imposed territorial divisions. Achieving such an NWFZ in Central Europe will certainly require a reexamination of some aspects of collective
security upon which the Atlantic Alliance is now based, as would the agreement to ban forward deployment of nuclear weapons in Central Europe discussed in earlier chapters.
Controlling Fissile Materials. Unprecedented international transparency and accountability for fissile materials are essential preconditions for achieving very low numbers of nuclear weapons. In the near- to medium-term, the United States can help lay the groundwork for these broader measures through two specific approaches.
The first is a worldwide ban on the production of fissile materials for nuclear explosives or the production of such materials outside international safeguards. A United Nations General Assembly resolution in 1993 called for negotiation of an international treaty of this kind at the Conference on Disarmament in Geneva. This would be the first such agreement that could include the undeclared nuclear powers, but so far these states have been reluctant to support it. The conference negotiations have been delayed because of resistance by the undeclared states to intrusive inspections and to freezing current stocks at unequal levels and because of the insistence of some nonnuclear weapons states that all states must acknowledge and account for their existing stocks. Although, at present, momentum for the start of serious negotiations has faded and early agreement is unlikely, a fissile material cutoff would be a significant nonproliferation measure and should continue to be strongly supported by the United States.
The second approach would address the problems presented by the civilian use of fissile materials, especially plutonium. U.S. leadership and active participation will be essential to improving International Atomic Energy Agency (IAEA) safeguards and to achieving measures for international civil plutonium management. Although highly-enriched uranium (HEU) is in some respects a greater proliferation risk, technical solutions for its management and disposition are straightforward and currently available.8 In any case, international control of all civilian as well as military fissile materials will surely come to be seen as a necessary part of reductions to very low levels of nuclear warheads.
New agreements should extend the high level of security and accounting demanded for intact nuclear weapons—the ''stored weapons standard"9— not only to all phases of the weapon disposition process but also to separated civilian plutonium and HEU worldwide. To this end, the United States should support transparency measures to declare all stocks of fissile materials worldwide, which would complement the declarations that all nonnuclear weapons states that are parties to the NPT are already required to provide to the IAEA.10 The U.S. Department of Energy took an important step in this direction in February 1996 with the release of a comprehensive report on the production, import and export, and current stocks and location of U.S. plutonium and has urged Russia to do the same.11
In addition, current U.S. efforts to encourage the conversion of research
reactors from HEU to LEU will relieve the dual-use problem by creating a demarcation between LEU as legitimate for research and power production and HEU as solely used for military purposes (weapons and naval nuclear reactors). Finally, although strong national and international export controls face problems of implementation and perceived discrimination, they do slow the spread of nuclear weapons materials and technology and are receiving increasingly strong international support through the voluntary London Suppliers Group and national legislation.
Reassuring States That Forego Nuclear Weapons: No-First-Use
The United States has not reassessed the array of positive and negative security assurances and guarantees it provided during the Cold War—and some it refused to provide—in order to bring these obligations in line with the dramatically changed international conditions. Any such reassessment will raise complex and difficult questions. How far is the United States willing to go in the defense of others—and how many others? How much flexibility is the United States willing to forego to build support for nonproliferation? Can U.S. conventional superiority be used to offer adequate deterrence and positive security assurances to replace the nuclear umbrella?
Taken together, positive and negative security assurances and guarantees help to reinforce the international consensus against the use of nuclear weapons. They also help reduce the incentives for other countries to acquire nuclear weapons. A commitment by the United States to maintain appropriately formulated positive and negative security assurances and guarantees, whether through defense cooperation or other means, is a fundamental element underlying the nonproliferation regime. Such commitments cannot be made lightly but, once made, will make a major contribution to stability.
It is probably not realistic at this time for the United States to be significantly more encompassing in its positive security assurances and guarantees, beyond those embodied in existing treaty commitments. Like the dilemmas faced by international collective security arrangements, clearly identifying who the aggressor is in a conflict and building the consensus to act against that nation may be difficult. The United States could, however, do more to make negative security assurances and guarantees serve its nonproliferation interests by constraining its own behavior—as negative assurances and guarantees do—in support of that cause.
To this end, the United States should announce that the only purpose of U.S. nuclear weapons is to deter nuclear attacks on the United States and its allies, adopting no first use for nuclear weapons as official declaratory policy. In the post-Cold War era, when nonproliferation is a high priority and the credibility of the nuclear powers' commitment to Article VI of the NPT is crucial to maintaining the international consensus behind the regime, a U.S. no-first-use pledge could help remove both reasons and excuses for proliferation. It would also assist with
the dialogue with China and those nonaligned states that urged a no-first-use declaration during the negotiations on the NPT and the CTBT and now propose a no-first-use treaty.
A no-first-use declaration would recognize that, in the changed circumstances following the end of the Cold War, the United States should not threaten to use nuclear weapons to deter nonnuclear attack. Such a declaratory policy would be consonant with the committee's proposed restriction of U.S. nuclear weapons to the core function of deterring nuclear threats. It would not in any way suggest that the United States is less willing than in the past to come to the defense of treaty-bound allies in Europe or Asia.
U.S. positive security guarantees to such allies have been an important component of not only regional and international stability but also U.S. nonproliferation policy: they relieve such states, and by extension the neighbors of such states, of the need to consider developing independent nuclear arsenals. Changing to a no-first-use policy will require consultation with allies to reassure them that the United States will meet, by nonnuclear means, its obligations to come to their aid in the event of nonnuclear attack. The use of U.S. nuclear forces would be reserved solely for deterrence of and response to nuclear attacks. So long as the conventional military superiority of the United States and its allies remains largely unchallenged, the substantial benefits of a no-first-use policy would out-weigh its small risks, provided the proper political groundwork is accomplished with NATO, South Korea, and Japan.
The recent change in Russian declaratory nuclear doctrine, from no first use to reserving a nuclear option in response to a conventional attack from any quarter, illustrates these transformed circumstances. The Russians now argue that they are at a serious conventional disadvantage vis-à-vis NATO and must therefore retain a nuclear first-use option.12 They argue further that NATO membership for states in Central Europe exacerbates this problem, as it carries with it an obligation to permit the basing of U.S. or NATO nuclear weapons in these countries.13 Such potential forward basing would feed Russian suspicions about the motives for NATO expansion; a negotiated ban on Russian and NATO forward basing of nuclear weapons, combined with the Central European NWFZ the committee recommends, would go far to allay these concerns, without reducing NATO security. A nuclear free zone could also help bring about a Russian recommitment to no first use, which is essential for achieving universal adherence to this standard.
The situation in Northeast Asia is similar. Despite the very real conventional threat posed by North Korea, the United States can achieve its deterrent and war-fighting objectives on the Korean peninsula without recourse to nuclear weapons. The U.S. security guarantee to Japan is especially important in the nonproliferation context: despite the profound Japanese aversion to nuclear weapons, Japan clearly possesses the technical wherewithal to acquire them. A Japanese nuclear capability would seriously destabilize the Asian-Pacific region and deal a severe
blow to the nonproliferation regime. But here again, given both the strength of the combined U.S.-Japanese and U.S.-South Korean conventional forces in the region, and the use by North Korea of U.S. nuclear threats as an excuse to acquire nuclear weapons, the threat of nuclear first use is both unnecessary and counterproductive for U.S. and allied security in the region.
Designing Responses to Future Proliferation
What actions should the United States take if one or more new states acquire nuclear weapons and use them to threaten or attack U.S. forces or allies overseas, or even the United States itself? To meet this possible future challenge, the United States needs to be prepared to take initiatives that will provide this country with greater leverage to impose sanctions on and otherwise coerce states that violate emerging norms of nonproliferation and nonaggression.
Responses Against Aggressive States and Terrorists. The current concept of "rogue" states emerged in U.S. policy circles in the late 1980s, driven by rising concern over the risks to U.S. interests from nations engaging in terrorism and aggression and seeking to arm themselves with nuclear, chemical, or biological weapons and the means to deliver them. More recently, in its support for the creation of the new Wassenaar Arrangement to control the diffusion of conventional weapons and dual-use technologies, the United States has made clear that Libya, Iran, Iraq, and North Korea are the primary focus of its concern.
Acquisition of nuclear weapons by any of these four states would be perceived to alter the political and military balance in its particular region. The impact would be moderated, however, because the same U.S. deterrence policy already in effect for other potential nuclear-armed adversaries would then apply to the newly nuclear states and their neighbors. Even without nuclear weapons, aggressive states could pose serious problems if they threaten U.S. friends and allies or if U.S. forces became engaged in a regional conflict. The United States should maintain armed forces adequate to meet its commitments and guarantee its own security with conventional arms.
Current U.S. policy tries to isolate those it considers aggressive states and, with varying degrees of success, attempts to persuade the international community to do the same. The continuing sanctions on Iraq in the wake of the Gulf War reflect an international consensus that Iraqi behavior is still unacceptable. U.S. efforts to persuade the international community that Iran deserves a similar isolation have not succeeded. In reality, most countries, including the United States, do not maintain consistently strict nonproliferation standards because nonproliferation concerns must compete with other bilateral or multilateral foreign policy interests. But U.S. interests would be best served by keeping up—and pressuring others to maintain—high standards in the handling of all nuclear technology exports to nonmembers of the NPT and to specific aggressive states.
Rather than opposing Russian assistance to the Iranian nuclear power program, for example, the United States should emphasize securing strict conditions for any cooperative and safeguarding activities. Like the North Korea case, sales of Russian equipment and technology represent a major opportunity to introduce international control of the fuel cycle in a country that might cross the line between civilian and military nuclear programs. The United States is supporting such conditions as the return of spent fuel to Russia, no-reprocessing and no-enrichment pledges, environmental monitoring, and formal agreement to anytime/anywhere IAEA inspections, which there is reason to believe that Iran would accept. By contrast, continuing U.S. attempts to prevent any nuclear trade with Iran are widely seen as contrary to Article IV of the NPT and as evidence that the United States believes that IAEA safeguards cannot be relied on to give timely warning of the diversion of fissile materials. It may also threaten wider U.S. relations with Russia, in particular gaining Russian cooperation on other important nonproliferation issues.
It is possible to construct scenarios for state-sponsored terrorists gaining access to a nuclear weapon. Detonation of a nuclear weapon in a U.S. city by terrorists would produce an immediate and overwhelming public demand for revenge, but nuclear response to nuclear terrorism where there is no established state sponsor is not feasible. And even for proven state-sponsored terrorists, the United States would have a range of options for retaliation, and a nuclear response should not be considered automatic for this case of nuclear use.
Responses Against Chemical and Biological Weapons Proliferation. One contentious area of current U.S. nuclear policy is whether nuclear weapons should be used to deter or respond to the use of chemical and biological weapons (CBW) by states against the United States, its military forces, or its allies. Some would have the United States enunciate an official policy of responding to CBW attacks with nuclear weapons, regardless of any negative security assurances to which it is committed. Others argue that the United States should make no explicit nuclear threat but allow or even encourage potential adversaries to assume the worst. This is the policy the United States followed in the Persian Gulf War. Former Secretary of State James Baker, for example, later wrote in his memoirs that at the time he "purposely left the impression that the use of chemical or biological agents by Iraq could invite tactical nuclear retaliation."14 As already noted, subsequent U.S. statements made in connection with its signing of Protocol I of the African Nuclear Weapons Free Zone treaty and with Senate consideration of the Chemical Weapons Convention have maintained that ambiguity.
Yet neither ambiguity nor an outright policy of nuclear retaliation serves long-term U.S. goals or interests. As the committee argued earlier, the United States should state that it will use nuclear weapons only to deter and respond to the use of nuclear weapons by others. The United States does not need and should not want to employ nuclear deterrence to answer CBW threats.
A policy of nuclear deterrence of CBW would provide incentives and an easy justification for nuclear proliferation, which is inimical to U.S. security. Many other countries face far more plausible and immediate CBW threats than the United States. If U.S. policy points to nuclear weapons as the ultimate answer to CBW, other states could have an increased motivation to acquire nuclear arsenals. Highlighting new or continuing missions for nuclear forces could damage the nuclear nonproliferation consensus throughout the world.
The United States has other means to deal with the CBW challenge that do not have negative consequences for U.S. security. The most fundamental response is to be found in the Chemical and Biological Weapons Conventions, which outlaw both classes of weapons and have reinforced a taboo against their use that has held up remarkably well. Despite rhetoric to the contrary, this barrier to CBW proliferation and use remains strong and, with entry into force of the Chemical Weapons Convention and current moves to strengthen the Biological Weapons Convention, promises to grow stronger over time. In cases where states or nonstate entities ignore these conventions and threaten the use of CBW, the threatened states can often take reasonably effective measures to protect military or civilian personnel from the effects of CBW (in contrast to the case of nuclear threats). International pressure—United Nations resolutions or sanctions and other means—also can be brought to bear on states claimed to be producing, or about to use, such weapons.
U.S. conventional forces offer a formidable deterrent and war-fighting response to CBW. The threat of conventional retaliation against CBW use is far more credible than the threat of nuclear attack for other, even more compelling reasons. First and foremost, a policy of nuclear retaliation endorses the very methods the United States condemns: the use of weapons of mass destruction. It would likely invoke nearly universal condemnation, in fact, thus casting a U.S. adversary in the role of victim, whatever the act that provoked the United States. This would almost certainly be the case if the physical consequences of a nuclear response carried beyond the boundaries of the immediate target area or the borders of the opponent. Finally, it is difficult to imagine a provocation so extreme that any U.S. president would want to breach the threshold of nonuse of nuclear weapons, which after all survived even the extreme threats and tensions of the Cold War. Indeed, the worst outcome of a nuclear response is the prospect that it might be seen as militarily successful, thus inspiring renewed belief that the perceived efficacy of nuclear weapons warrants their retention or, worse, acquisition.
NUCLEAR FORCE REDUCTIONS: HOW LOW CAN WE GO?
Thus far this report has considered the broad operational and policy issues whose resolution should be part of the process of achieving the conditions for truly low levels of nuclear armaments. The final part of this chapter discusses two further stages of the nuclear arms reduction process beyond START III: first,
the committee recommends a commitment to reduce nuclear weapons to a total inventory of about 1,000 warheads each; then the merits of still deeper cuts, to totals of a few hundred each in the U.S. and Russian arsenals, and the issues that would need to be addressed to make such deep cuts practical are examined.
Critics of proposals for deep nuclear arms reductions argue that such cuts could actually be counterproductive for a number of reasons:
Large nuclear arsenals could help prevent proliferation. Potential proliferators will be discouraged from acquiring nuclear weapons because, as long as the declared nuclear weapons states, in particular Russia and the United States, maintain large arsenals, a potential proliferator could not possibly aspire to join the "big league" of the major nuclear powers. Once the nuclear weapons states agree to reduce their arsenals by substantial amounts, attaining relatively significant nuclear status will become easier, and hence potentially more attractive.
Historically, possession of nuclear weapons has bestowed international prestige. By substantially reducing their nuclear arsenals, the United States and particularly Russia could find their relative prestige diminished.
Since the major nations, including the United States, have renounced the use of chemical and biological weapons, nuclear weapons are the principal deterrent against CW and BW threat and use. Decreasing nuclear weapons deployments amounts to unilateral disarmament vis-à-vis potential BW and CW threats from rogue nations.
The committee believes that these arguments should not be a barrier to deep nuclear arms reductions:
The motives of today's potential proliferators to acquire nuclear weapons are often determined by regional factors, as is discussed elsewhere in this report. The size alone of the nuclear weapons deployments of the major powers is unlikely often to be a significant factor in the decision of new states to seek a nuclear weapons capability.
In the post-Cold War world, the committee believes the prestige of the United States is based on other factors that are more important than the size of its nuclear arsenal. Russia's longer-term status is far more dependent on its economic revival and political stability than on the size of its nuclear arsenal. With regard to nonnuclear weapons states, the important status attained by states such as Germany and Japan, and the lack of special status accorded to India, Israel, and Pakistan, as well as North Korea and Iran, countries that have or have sought nuclear weapons, should be noted.
As discussed in Chapter 2, the committee believes that "weapons of mass destruction" is a misnomer that obscures militarily important differences among nuclear, chemical, and biological weapons. The issue of using
nuclear weapons to deter the use of CBW was discussed in a previous section, where the committee concluded that CBW threats can be deterred and effectively countered without relying on nuclear weapons.
Reducing U.S. and Russian Forces to 1,000 Total Warheads Each
Let us assume that the United States and Russia have achieved reductions to about 2,000 deployed strategic warheads each through a START III agreement. What should be the next step by the United States? We could move directly to the lowest possible level that would permit us to fulfill the core deterrent function. Or we could proceed more conservatively in steps to that goal. The committee chooses the latter for two reasons: first, in the present analysis the committee wants to provide the numbers—and the rationale for those numbers—at every stage in the reduction process to illustrate both its feasibility and its practicality; second, the committee proposes that, at the earliest possible time, the unit of account for nuclear weapons should become any nuclear warhead in the possession of a state, not just deployed strategic warheads. The problem of adopting such a unit of account is not the physical task of dismantling and destroying warheads but the far more difficult and crucial issue of accountability. Both the United States and Russia, and later other states, will need very high levels of assurance that all warheads have been included in such a regime and that remaining warheads can be accounted for. Between the 2,000 accountable strategic warheads of START III and the lowest level of deployed systems possible, the committee has chosen the level of about 1,000 total warheads in the inventory of each country as a logical intermediate stage.
Why only about 1,000 warheads? There are three important issues: (1) survivability; (2) the need to be able to perform the core deterrent function without question; and (3) the problem of the other declared nuclear powers.
Survivability. The general process of nuclear reductions outlined in this report involves a continuous effort to seek lower levels of risk and higher levels of U.S., allied, and global cooperation and security from nuclear attack. To achieve such benefits, however, the process must ensure stability at each rung of the ladder, and stability is most clearly guaranteed by the possession of survivable nuclear forces not at risk from a first strike. At a level of about 1,000 warheads, such survivability can be assured for the United States through the deployment of Trident ballistic missile submarines carrying appropriately downloaded missiles. This level also offers the Russian government the option to place a greater proportion of its nuclear forces in a survivable posture at sea or in land-mobile missiles out of garrison should it choose to do so.
Performance of the Core Function. The earlier discussion of targeting doctrine provides a second reason for seeking post-START III reductions with Rus-
sia to about 1,000 warheads. A force of this size would be able to maintain the core function satisfactorily against the most challenging potential U.S. adversaries under any credible circumstances, assuming that strategic defenses remain limited and transparent enough to avoid surprises. Nor does the committee see a need for a reserve nuclear weapons stockpile as a hedge against the emergence of new nuclear powers or clandestine expansion of the nuclear arsenals of existing nuclear weapons states.
The Other Declared Nuclear Powers. The nuclear arsenals of the other declared nuclear powers—China, France, and the United Kingdom—provide a third rationale for the proposed level of about 1,000 warheads. Given their current policies, discussed in Chapter 2, these countries would seem to pose no impediment to an otherwise desirable reduction of U.S. and Russian holdings to about 1,000 total warheads each. As long as these three countries pledge not to increase their nuclear forces and hold open the possibility of eventual reductions, the United States and Russia can reduce to a level of roughly 1,000 warheads without demanding reductions in their arsenals as a precondition.
Before examining the next stage in this reduction strategy, the committee wants to emphasize that its shift from accounting for delivery vehicles to warhead accountability does not suggest that delivery vehicles are no longer important. On the contrary, the accountability established in the INF treaty for missiles and in START I for missiles and bombers must be sustained and expanded. Verification measures for these systems have been tested and perfected over the years and should be continued.
Nonetheless, the accountability problems relating to a warhead count pose unique and significant difficulties. Information about some of the numbers and types of warheads maintained by the United States and Russia remains classified, although they have been described extensively in nongovernmental publications. The status and condition of warheads likewise relates directly to perceived requirements for a functioning system of nuclear deterrence. Even as the conditions set forth here for progress in this area are met, the committee admits that tough negotiations are ahead and even greater levels of U.S.-Russian transparency and cooperation will be required.
Other measures have already been undertaken to account for nuclear warheads and their components. In addition to the verification measures discussed in Chapter 2, a system of material protection, control, and accounting is being developed for components of the surplus weapons of the former Soviet Union as they are dismantled under START I. Funded by the United States under the Cooperative Threat Reduction Program established by the 1991 Nunn-Lugar legislation, this effort has the goal of reducing the risks of nuclear weapons proliferation, including such threats as theft, diversion, and unauthorized possession of nuclear materials. Some of the progress made and the systems developed could be directly applicable to a warhead accountability system for weapons remaining in military hands.
Reducing to a Few Hundred Warheads
Even the achievement of U.S.-Russian reductions to a mutually agreed level of about 1,000 total warheads should not represent the final level of nuclear arms. There will still be powerful reasons to continue down to a level of a few hundred nuclear warheads on each side, with the other three declared nuclear powers at lower levels or perhaps even with no remaining nuclear forces.
The case for reductions to a few hundred warheads each for Russia and the United States rests on the same basic arguments as that for reducing the numbers of nuclear arms in general. These deeper cuts will continue the process toward constraining nuclear weapons that was begun by earlier reductions. Reduction to below 1,000 total warheads each in the U.S. and Russian arsenals, as a major step toward mitigating the discrimination inherent in the current nonproliferation regime, will be significant for long-term success of the global nonproliferation enterprise. While the danger of unintended use of nuclear weapons would be smaller at a level of 1,000 warheads than it is now, moving to the level of a few hundred nuclear weapons would further reduce the risks of erroneous or unauthorized use. Finally, such reductions would further constrict the scope foreseen for any conceivable intentional use of nuclear weapons.
Reduction to 2,000 deployed strategic warheads could accomplished in a few years; while moving to 1,000 total warheads will take somewhat longer, it is still a bilateral action. To go on to a few hundred, however, will be a more complicated and multilateral process.
Conditions for Reductions to a Few Hundred Warheads. One particular measure the committee recommends as a precondition for low levels of nuclear forces should be emphasized: an even more effective warhead accountability regime. Verification of forces as low as a few hundred nuclear weapons requires a standard significantly more exacting than attainable by current capability and knowledge. While survivable nuclear forces at this level would offer each nuclear power important insurance against the covert retention or acquisition of illegal nuclear warheads by another state, the nuclear powers would certainly insist on reliable accounting of the residual existing warheads before they would agree to move toward such small arsenals. How well and how quickly the nuclear powers—especially Russia and the United States—are willing to account precisely to each other for the warheads they produced during the Cold War will go a long way toward determining the perceived feasibility of, and a realistic timetable for, reductions below 1,000 warheads.
This analysis does not assume a fundamental change in the nature of international relations in order to achieve low levels of nuclear arms. It does assume unprecedented cooperation and transparency among all classes of nuclear powers—first tier, second tier, and undeclared—on the specific issue of nuclear arms reductions. Success in engaging the undeclared states and the willingness of the second-tier nuclear powers to allow reductions—or even elimination—of their
nuclear weapons will be essential. So will enhancements to the effectiveness of the nonproliferation regime. Such cooperation and enhancements, although conceivable with the present state of world politics, would become more feasible once the process of nuclear reductions and a growth of confidence in its basic soundness and stability, has proceeded for another decade or so.
The remaining nuclear forces would have to be survivable, their command-and-control structure would have to be redundant and robust, and widespread and effective national ballistic missile defenses must be absent. Moreover, even at this low level the committee does not see a need for a reserve nuclear weapons stockpile as a hedge against the emergence of new nuclear powers or clandestine expansion of the nuclear arsenals of existing nuclear weapons states.
The Size and Composition of Small Nuclear Forces. A level of roughly 300 warheads provides a somewhat arbitrary but nonetheless useful model for discussing this phase of arms reductions. From a purely technical point of view, roughly 300 nuclear weapons—of which at least 100 were secure, survivable, and deliverable—should be adequate to preserve the core function.
The committee recognizes that a progressive downward revision from the current levels of nuclear arms, and even from the lower numbers recommended in the previous stage, to a level of a few hundred deliverable warheads implies a drastic change in strategic target planning. A force of a few hundred can no longer hold at risk a wide spectrum of the assets of a large opponent, including its leadership, key bases, communication nodes, troop concentrations, and the variety of counterforce targets now included in the target lists. The reduced number of weapons would be sufficient to fulfill the core function, however, through its potential to destroy essential elements of the society or economy of any possible attacker.
Many suggestions have been made for force composition at the level of a few hundred, such as eliminating all intercontinental ballistic missiles, retaining only the strategic submarine force, or basing nuclear-capable aircraft in a dispersed mode. The committee does not recommend a particular approach, and it is likely and acceptable that different nuclear powers would choose different options, but one U.S. example is offered here to demonstrate the viability of the concept.
Consider a U.S. nuclear deterrent based only on submarines. Maintaining two survivable nuclear ballistic missile submarines (SSBNs) continuously at sea would require five in the inventory; at any given moment, two of the five may be assumed to be in port and one might be undergoing repairs or refitting. To maintain two fully survivable submarines at sea in both the Atlantic and the Pacific oceans would thus require 10 total SSBNs in the U.S. force. Assuming the current level of 24 missile tubes per Trident submarine, and a loading of one warhead per missile, this force would possess 240 operational warheads, of which some 100 would be kept at sea and survivable at any given time. Adding 60 additional
warheads for spares, logistics, and refurbishment produces a total of 300 warheads in the inventory—one-third of which are survivable on a day-to-day basis.
This example assumes the use of current U.S. submarines and submarine operational procedures. In a period of heightened tensions that lasted up to several months, a larger fraction of the force could be deployed at sea, increasing the number of survivable weapons (and reducing the vulnerability of large numbers of nuclear weapons sitting on submarines in port). In the longer run, as the U.S. Trident submarines ended their operational lives, the United States could replace them with a generation of smaller submarines carrying fewer missiles, thereby increasing the number of survivable platforms held at sea.
In the operational posture of much smaller nuclear forces, the elements of the force would be designed for deliberate response rather than reaction in a matter of minutes. States could assure this result through transparency measures to make it clear that preemptive attack and instantaneous retaliation, including launch under real or perceived attack, are no longer feasible options. This might be achieved, for example, by separating weapons from delivery systems. Where this is impossible or extremely difficult, such as on submarines at sea, it can be achieved by limiting the range of missiles (by removing stages and/or adding ballast) and restricting the area in which the submarines might operate. In any case, the highest standards of protection against unauthorized use should be implemented on the nuclear delivery systems of all countries.
Other Issues at the Level of a Few Hundred Warheads. An infrastructure of nuclear weapons expertise sufficient to maintain the safety and reliability of the remaining nuclear weapons will be required. This infrastructure must be sufficiently transparent to provide accountability of the total number of nuclear weapons and to assure the international community that it is not being used for the development of additional types of weapons. Maintenance of such an infrastructure, including continued availability of highly capable technical personnel, should not be interpreted as contrary to achieving reductions. The reductions in nuclear forces advocated by the committee will also permit postponement of any decision on the preferred approach to meet further tritium requirements for several decades.
Managing and disposing of excess stocks of plutonium and HEU will pose a growing problem for the world. These excess fissionable materials derive from the dismantlement of surplus weapons stockpiles and from other military programs as well as from spent fuel in the civilian nuclear fuel cycle. While it will be a lengthy and continuing process, it is necessary and feasible to achieve the ''spent fuel standard," in which all excess plutonium would be no more accessible and attractive for weapons fabrication than that in the spent fuel of commercial power reactors.15 It will be necessary, of course, to ensure that commercial spent fuel is adequately protected worldwide. As discussed earlier, a related
goal should eventually be to subject all stocks of fissile materials to the "stored weapons standard."
Strategic Stability at Low Levels. When examining the risk of small numbers of nuclear weapons, two issues must be addressed:
Can the transition down to a level of a few hundred nuclear weapons be made without crossing a zone of increased instability, which could increase the risk of preemptive attack in a crisis?
Will defenses enhance or decrease stability during the transition to small numbers of nuclear weapons?
The answer to the first question depends, most importantly, on the broader political and strategic situation prevailing among the nuclear weapons states. Reductions to the level of a few hundred nuclear weapons can be achieved without incurring instability by carefully managing the stages of the process, particularly the precise sequence in which delivery systems are reduced. In general, instabilities can be avoided if, among other measures, the more vulnerable systems are retired first, multiple-warhead missiles are eliminated (thereby decreasing the value of a single aim point), and the time at sea for submarine forces (which also must be controlled by effective permissive action links) is maximized.
Some will also ask whether ballistic missile defenses could eventually provide adequate insurance against deliberate or accidental launch of a small number of retained or clandestinely produced nuclear weapons once the nuclear powers move toward very small nuclear forces. Point defenses could have a limited value in increasing the survivability of any remaining fixed land-based nuclear strategic systems. But more elaborate defenses are incompatible with the program of major reductions, since such systems could at least be perceived as negating the deterrent value of a deployed force of a few hundred weapons. Moreover, given the large number of means available for delivering nuclear weapons, it is difficult to imagine a world in which clandestine delivery could be effectively prevented. Thus, it seems likely that the deployment of defenses capable of intercepting significant numbers of strategic ballistic missiles would prevent major arms reductions without adding to security.
Ballistic missiles designed for shorter ranges and the delivery of conventional munitions will probably remain in military arsenals while the process of nuclear arms reduction proposed here proceeds. Such ballistic missile deployments will in turn presumably motivate missile defenses designed to counter such regional and theater threats. The committee considers such deployments to be part of the continuing evolution of conventional military postures. The committee does not address the prospects for success of ongoing efforts to restrain the proliferation of ballistic missile technology, although it is important to recognize that states can rapidly convert conventionally armed ballistic missiles to carry
nuclear warheads if such warheads are available. Thus, controls on nuclear weapons remain paramount. And any controls on ballistic missiles of a particular range must apply to all such missiles, not merely those their possessors claim are armed with nuclear warheads. For this reason, in the INF treaty the United States and the Soviet Union agreed to a worldwide ban on their possession of land-based missiles with ranges of 500 to 5,500 kilometers, whether nuclear armed or not.
How soon the United States and Russia could move to a level of a few hundred warheads, and the other three declared nuclear powers to equal or lower levels (or perhaps zero), would depend more on political than technical factors. Not only the United States but also Russia, for example, would have to perceive a growing momentum toward political and military stabilization in which cooperation with the other nuclear powers played a role. Russia's economic health, if not prosperity, would likewise be important to its willingness to proceed to a level that in nuclear terms would "equalize it" with the United States, United Kingdom, and France but also with China. The main technical issues regarding deep reductions are achieving an effective verification regime and maintaining survivability and the ability to reach targets as discussed above. By comparison with the political and other technical barriers—especially verification—to be overcome, the technical task of dismantling the additional numbers of nuclear weapons made surplus by such reductions is a modest one. Once the preconditions for a multilateral accord to reduce to a few hundred warheads were met, states could move relatively quickly from the 1,000 level to lower numbers of nuclear arms.