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Nuclear Weapons after the Cold War

By W.K.H. Panofsky

W. K. H. Panofsky Photo credit: AIP Emilio Segre Visual Archives, Panofsky Collection

The Cold War is over but little has changed in respect to US nuclear weapons policy. Yet the nature of the threats to US security from nuclear weapons has shifted dramatically since the end of World War II. Today the likelihood of deliberate large-scale nuclear attack against the US is much less than the risk of a nuclear weapon accident, unauthorized use, or the threat from the proliferation of nuclear weapons across the globe.

During the Cold War we saw a dramatic nuclear build-up, reaching a rate on the US side of more than 5,000 weapons per year. The current shift to a build-down of nuclear weapons, proceeds at a rate of around 1,500 per year. The peak of the build-up "enriched" the world with over 60,000 nuclear weapons-an insane figure on its face-considering that two nuclear weapons, with the explosive power of about one-tenth of the average weapons in current stockpiles, killed a quarter million people in Japan. The build-down has cut the Cold War peak by only about one-half.

One reason for this is that nuclear weapons have become symbols of political power, with their physical reality relegated into oblivion. We as physicists have a major responsibility to maintain public awareness of the awesome reality of nuclear weapons. This task is made even more difficult in that, thanks to the non-use of nuclear weapons since 1945 and the cessation of atmospheric nuclear tests, few have ever seen a nuclear explosion. The second reason for this vast nuclear arsenal has been the extension of the proclaimed utility of nuclear weapons beyond their "core mission." This concept of extended deterrence — using nuclear weapons to deter threats posed by non-nuclear, meaning conventional, chemical and biological weapons, or to use the threat of nuclear weapons to protect the interests of other nations — denied the policy makers a meaningful answer to the fateful question "When is enough, enough?"

All this is now behind us — or is it? Nuclear weapons are still viewed by many as symbols of power. The recent nuclear tests by India and Pakistan were largely motivated by politics, not by a profound and realistic analysis of security needs. The latest full review of US policy concerning nuclear weapons - the Nuclear Posture Review (NPR) of 1994 — retained a great deal of Cold War thinking. The magnitude of "required" forces was still determined by a list of thousands of nuclear targets which had to be covered. The policy underlying the NPR was designated as "reduce and hedge," meaning that, while the reducing trend illustrated should be continued, large non-deployed stockpiles should be retained in order to re-equip US nuclear delivery systems with additional warheads should a more hostile Russia reemerge. Since that time, there has only been one additional revision of official US nuclear weapons policy, which occurred last year. The only change was that the US should no longer be prepared to fight a "protracted" nuclear war, but be able to reply to a large variety of threats by a single response.

These official policies tended to subordinate the threat to a role distinctly secondary to the need of nuclear weapons to counter a large spectrum of specified conjectured threats. Yet the threat of nuclear proliferation is largest to the US. among all other nations. Being the world's dominant power politically, we have most to lose if nuclear weapons proliferate. Nuclear weapons concentrate the destructive energy which can be delivered by any vehicle carrying weapons of a given size and weight by a factor of approximately one million. They are in many respects the "great equalizer" among nations, in the same sense that in the Middle Ages, firearms equalized the power of the physically weak and physically strong individuals.

Potential proliferants can deliver small numbers of nuclear weapons in many ways. Note that the US developed a nuclear projectile system, the Davy Crockett, which could be handled by a single soldier. Thus nuclear weapons could be detonated on ships in harbor, delivered by light aircraft, smuggled across US boundaries, and deployed by ballistic and cruise missiles of a variety of ranges. Meaningful defense against such a spectrum of delivery options is impossible; defense of this country against hostile detonation must rely on dissuasion, not physical intercept. Dissuasion has many facets, some diplomatic, some military, including deterrence of the potential user of nuclear weapons through likely nuclear retaliation, and arms control. There is no evidence that deterrence is any less effective against "rogue" nations than it is against current member states of the nuclear club, including Russia or China, who have been technically capable of delivering nuclear weapons against the US for a long time.

A major effort to stem the proliferation of nuclear weapons culminated in the Nuclear Nonproliferation Treaty (NPT) in 1970, which was converted in 1995 into a treaty of indefinite duration. This treaty has been signed by more nations than signed the United Nations Charter, and its signatories are divided into 181 Non Nuclear Weapons States and five Nuclear Weapons States. Thus the NPT in essence is discriminatory. The Non Nuclear Weapons States signatories were persuaded that their national security would be better served by not possessing nuclear weapons than by owning them.

The nuclear nonproliferation regime as enshrined in the NPT encompasses a complex bargain. The Non Nuclear Weapons States signatories agree not to develop or to receive nuclear weapons and the Nuclear Weapons States agree not to furnish them to Non Nuclear Weapons States. A provision often forgotten is that Nuclear Weapons States agree to assist Non Nuclear Weapons States in the development of the peaceful applications of nuclear energy: nuclear power and medical and research applications. Above all, the Nuclear Weapons States agree to reduce the role of nuclear weapons as instruments of international policy, decrease their numbers, and work in good faith towards their eventual prohibition.

It is in this last respect that the Nuclear Weapons States are expected to face the most severe criticism: they will be rightfully accused to have not lived up to their side of the bargain. The arms control process has been stalled for some years. This failure will expose the US and Russia in particular to severe criticism in the next NPT review conference, scheduled for the year 2000. The commitment to erase the discriminatory nature of the NPT regime overtime by a regime of progressive restraint leading to eventual prohibition is an essential element of the NPT bargain. The Treaty is unlikely to endure indefinitely without the Nuclear Weapons States giving much higher priority to their obligations in this respect. I consider it extremely important to revitalize the arms control process; the future of world civilization remains at risk unless much more progress is made. Erasing the discriminatory nature of the present nonproliferation regime over time is a necessity and the US should take the lead in this quest. With its vast superiority in so many areas beyond nuclear weapons, the US has most to gain and least to lose by exercising such leadership.

The effort to stem proliferation of weapons based on new technology is indeed daunting. Never before has mankind succeeded in stemming proliferation of a new technology towards military goals once that new technology led to civilian applications. Thus, while preventing proliferation of nuclear weapons is an overriding necessity, such an achievement would be unprecedented in history. There is little question that today both the US and Russia possess excess nuclear weapons beyond reasonable national security needs. Yet the legislatures of both countries seem to be engaged in a race with one another as to who can most act against their own national security interests. Further, major reductions on both sides, agreements between the Executive branches, or reciprocal unilateral moves, are clearly desirable to reduce burdens in maintaining the residual stockpiles, and to reduce the chances of accidents or inadvertent use. The latter risk is a particular problem with respect to Russia today, since controls are eroding and the Russian Early Warning System has severely deteriorated.

Several proposals for further reductions have been made. The agreements reached by Presidents Clinton and Yeltsin at the summit in Helsinki provide for initiating negotiations toward a START III Treaty, reduce strategic stockpiles on both sides to the sub-2,000 level and which would initiate discussions on future provisions to cover nuclear warheads of all kinds. However, the US has unwisely linked initiation of START III talks to Russian ratification of START II, which is lingering in the Russian parliament and where the recent deteriorating US-Russian relations has extended that period of inaction.

In my view, US national security for the foreseeable future would be well served by a reciprocal reduction regime leading to a level of "a few hundred" nuclear weapons on the part of the US and Russia, which roughly matches the inventories of the other Nuclear Weapons States — China, France and the UK. At that level, nuclear weapons are still ample to discharge the "core mission" of deterrence. Restriction to this core purpose is tantamount to a policy of "no first use" in contradiction to the current policy of extended deterrence. It is worth noting that recently Germany and Canada, two NATO allies, have proposed that serious consideration be given for NATO to adopt a no-first-use doctrine; these proposals will receive some consideration at the NATO conference to be held later this year. These progressive restraints would go a long way in discharging the perceived obligations of the Nuclear Weapons States under the NPT, while still protecting US interests against hostile actions by other states. Yet such drastic reductions remain controversial despite the evident logic of the arguments supporting them.

All this begs the fundamental question: Can conditions ever be achieved in which the possession and use of nuclear weapons can be prohibited worldwide? Nuclear weapons cannot be "un-invented." Thus the best hope for mankind is to arrive at an international norm under which nuclear weapons are prohibited in just the same manner as an international norm exists today for prohibition, possession, and use of chemical and biological weapons. Such a norm would not reduce the risk to zero. There remains the risk of clandestine retention of nuclear weapons by those states now possessing them and the clandestine manufacture of nuclear weapons by "rogue" states and perhaps even sub-national groups. Obviously many steps can be taken to minimize such risks. However, the ultimate question remains whether the security of the US and the world is served better by accepting such residual risks, rather than living with the extremely dangerous and fragile situation we are facing today.

Today we are facing the problem of having issues such as these even considered by the public and the body politic. So many other events preempt the news and the political agenda. Indeed, the world is fortunate that nuclear weapons have not been used in anger since 1945, and that the "near accidents" involving nuclear weapons never resulted in a nuclear explosion. Yet the world cannot afford to postpone action severely restricting the number and use of nuclear weapons until a nuclear detonation actually occurs.

Wolfgang K. H. Panofsky is Director Emeritus of the Stanford Linear Accelerator. This article was adapted from his paper given at the APS Centennial Meeting in Atlanta, GA, on March 24, 1999. The full version can be found online at: http://physics.wm.edu/˜sher/aapr99.cfm#a3