The Unfinished Work of Arms Control

The world got through the half century since Hiroshima and Nagasaki with no further use of nuclear weapons in conflict and with a degree of restraint in avoiding major war among the great powers that could very well have been due to the cautionary influence exerted by the existence of nuclear weapons. But the nuclear weapons era has entailed considerable costs and dangers-above all the risk that the unimaginable destruction of nuclear war would be unleashed by accident or error or by escalation from a conventional conflict or a crisis. Also, the risk has always been present that the major powers’ prominent reliance on nuclear deterrence and the possible use of nuclear weapons in war fighting would promote nuclear proliferation among more and more countries.

With the Cold War over, the danger of premeditated nuclear war with Russia has practically disappeared, and the conventional military threats once thought to require deterrence with nuclear weapons are likewise much diminished. The United States and Russia have taken advantage of these fundamental changes with a series of major agreements and unilateral initiatives. Under the terms of the first Strategic Arms Reduction Treaty (START I), signed in 1991 and currently being implemented by both countries, the number of strategic nuclear warheads deployed by the two sides will be cut from 13,000 and 11,000, respectively, to about 8,000 each. START II, signed in 1993, would further limit the number of deployed strategic warheads to 3,000 to 3,500 on each side; the United States ratified the treaty in early 1996, but Russia has not yet done so. At the Helsinki summit in March 1997, Presidents Clinton and Yeltsin agreed to seek a START III treaty with a level of 4,000 to 4,500 deployed strategic nuclear warheads. Unilateral initiatives since the early 1990s have also significantly reduced the numbers of deployed nonstrategic warheads, especially on the U.S. side. Nuclear testing has ended and the United States and Russia have agreed not to target their missiles against each other on a day-to-day basis. Perhaps most important, a debate has begun on the proper role and function of nuclear weapons in the long run.

Despite this remarkable progress in reducing the number of nuclear weapons, neither the basic character of U.S. and Russian nuclear forces nor the plans and policies for their use have fundamentally changed from what they were during the Cold War. This leaves us with nuclear postures, and associated costs and risks, out of proportion to the diminished demands on these forces in the post-Cold War world. For example, both the United States and Russia continue to maintain a significant portion of their nuclear forces in a state of alert that would permit them to launch thousands of nuclear warheads in a matter of minutes. These continuous-alert practices exacerbate the risk of erroneous or unauthorized use. As long as one side maintains its forces in a state of high alert, it is politically unrealistic to expect the other side to lower its guard. And Russia recently announced that to offset the weakness of its conventional forces, it is adopting for its nuclear weapons a “first-use-if-necessary” doctrine similar to that of the United States and NATO, thus apparently giving nuclear weapons a more central role in its national security.

Moreover, the size of these arsenals, even after START I and (we hope) START II are implemented, will remain larger than necessary for deterrence. Also, the risk that other countries might obtain nuclear weapons remains serious and requires continuing high-priority attention.

Fundamental change needed

To respond fully to the opportunities to reduce nuclear dangers opened by the end of the Cold War, the United States should adopt a fundamental principle: The role of nuclear weapons should be restricted to deterring or responding to a nuclear attack against the United States and its allies-that is, the United States would not threaten to respond with nuclear weapons to attacks by conventional, chemical, or biological weapons. Limiting nuclear deterrence to its “core function” would permit significant measures to further reduce the risks posed by nuclear weapons, including changes in nuclear operations and improvements in the safety and survivability of nuclear weapons. Adequately sized and properly equipped conventional forces would be essential in providing an effective response to nonnuclear threats. Consonant with this approach, of course, the United States must meet its own security requirements and its commitments to friends and allies. And it must take great care to reassure its allies that those commitments will be kept.

Since the Persian Gulf War, there has been considerable discussion about whether nuclear weapons should be used to deter chemical and biological weapons. It is a serious misnomer to lump the three types of weapons together under the label “weapons of mass destruction.” In reality, these are very different types of weapons in terms of lethality, of certainty of destruction, and of their relative effectiveness against military targets. Chemical and especially biological weapons are serious and growing problems for international security. But nuclear weapons are not the answer to the most likely uses of chemical and biological weapons against the United States or its allies.

Restricting nuclear weapons to the core deterrence function would permit a number of significant changes. First, the United States should make no first use of nuclear weapons its explicit doctrine-and encourage Russia to do the same-rather than continuing to adhere to “first-use-if-necessary” for nuclear weapons. This would allow for much deeper reductions in the U.S. nuclear arsenal. Provided that the remaining nuclear forces are survivable and their command-and-control systems are robust, just a few hundred warheads might satisfactorily fulfill this core deterrent function. Reaching such low levels will obviously have to be accomplished in stages, and very significant improvements in our verification capabilities will be required to ensure that small numbers of nuclear weapons are not hidden away for deleterious purposes. Also, other countries, both declared and undeclared nuclear powers, must be included in a regime of nuclear arms reductions before the United States and Russia could prudently reduce the number of their warheads below 1,000.

Short-term steps

Among the short-term measures to be taken, two seem particularly important to restore momentum toward fulfilling the unfinished agenda of reducing the nuclear danger.

Jump-start START. Serious discussions should begin immediately to outline the details of the proposed START III agreement, rather than waiting for START II to take effect. The current policy of demanding Russian ratification of START II before discussions begin gives the Russian Duma too much leverage over the arms control process and could cause unnecessary delay when (and if) ratification is achieved.

In addition, START III should be negotiated under the counting rules created in START I and II, which count deployed delivery systems and then assess a count of deployed strategic warheads indirectly, in order to enable us to reach early agreement. The difficulty of agreeing on the details of a change to counting total warheads-and actually doing the counting-is more of a burden than the next round of reductions should have to bear. Future agreements beyond START III, however, should encompass all nuclear warheads: strategic and nonstrategic, active and reserve.

Prune the nuclear hedge. The 1994 Nuclear Posture Review, carried out by the Department of Defense, is the basis of current U.S. policy. A key factor in the review’s conclusions was the perceived need to retain U.S. flexibility in case reform in Russia failed. As a result, the United States opted to maintain a “hedge” of additional reserve warheads to provide the ability to reconstitute its nuclear forces if it became necessary. But additional firepower would not improve the practical deterrent effect of U.S. nuclear forces in the event of renewed antagonism with Russia. Moreover, the need to increase its strategic readiness in ways open to intelligence gathering systems-for example, by dispersing bombers or by moving a larger fraction of its ballistic missile submarine force to patrol areas-would provide a genuine hedge against surprise. The United States would only need to increase its nuclear force levels if massive growth in the Russian force imperiled the survivability of the U.S. arsenal; for the foreseeable future Russia has no realistic capability for such reconstitution.

The primary risk posed by the hedge strategy is that it could become a self-fulfilling prophecy: The United States may consider keeping a substantial stock of reserve warheads a matter of prudence, but to Russia it could look very much like an institutionalized capability to break out of the START agreements. To the extent that the United States is concerned about a return to hostile relations with Russia, it should focus on decreasing the probability of such perceptions.

Abandoning the hedge would also save several billion dollars a year and ease the burden on the Department of Energy in maintaining the reliability and safety of an oversized nuclear stockpile. In the absence of a compelling security requirement, it makes good budgetary and military sense to reduce the number of warheads.

Two other important short-term measures require serious technical study and analysis to make their implementation possible:

Providing greater operational safety. In parallel with but not directly tied to the START III discussions, the United States should begin seeking measures to provide higher levels of operational safety for nuclear weapons. Technical discussions with the Russians should begin as soon as possible so that any unilateral moves might be readily reciprocated. At present, “dealerting”-measures to extend the time it would take to prepare nuclear weapons for launching-is receiving considerable attention. Serious detailed studies are needed from the military-technical community to provide the basis for implementing this idea. And any agreed reduction in alert status would have to be accompanied by reliable means of assuring compliance, an essential element of which would be a warhead accountability system.

Although it is relatively easy to describe the idea of “dealerting,” achieving it without destabilizing consequences will not be trivial. To the extent that we are concerned about the safety and security of Russian strategic nuclear forces, however, such measures are the most direct remedy. More broadly, ending continuous-alert practices would be a significant step toward reducing the dangers of a hair-trigger posture.

Counting all warheads. At the Helsinki summit in March 1997, Presidents Clinton and Yeltsin agreed to begin exploring how to move toward a regime that uses warheads-all warheads, not just those deployed-rather than delivery vehicles as the unit of account. This is an essential step for deep reductions in nuclear weapons; countries will not agree to cut their arsenals to minimum levels if they cannot be assured that significant stocks of nuclear warheads are not hidden away. It is also a formidable verification challenge, requiring advances in technology considerably beyond what is available today.

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 provide confidence that there will be few incentives to cheat or that violations, when detected, will be dealt with swiftly. It emphasizes the necessity for our own security to maintain conventional forces capable of executing whatever tasks they are called upon to perform. It also highlights the importance for the United States of maintaining stability through equality with Russia during any prolonged period of reductions.

The unfinished agenda for arms reductions thus includes significant political and technical challenges. But we have found remarkable agreement, both within and outside the government and in the international community as a whole, that this is the agenda that must be pursued. The consensus about the role and future of nuclear weapons has changed dramatically since the end of the Cold War. Many once almost unthinkable policy options have now become issues of “when” and “how,” not “whether.” Some of the agenda items are controversial and may not be implemented soon. But we are beyond the stage of philosophical debate and into the realm of wrestling to form workable policy choices and strategies to carry them out.