Since the demise of the Soviet Union, Washington's strategic thinking about nuclear weapons has evolved in dangerous and unwise directions. In January 2002, the Bush administration announced a new nuclear posture, which it reiterated in 2006. But instead of doing what it claimed it would do -- adapt American nuclear strategy to the realities of the twenty-first century -- the administration has focused on addressing threats that either no longer exist or never required a nuclear response. Rather than protecting the United States, this posture constitutes a danger to U.S. security.

The risks posed by nuclear weapons today are daunting, but rarely in the same ways that they used to be. As the nuclear club has expanded since the end of the Cold War, so have the dangers posed by the possibility of an inadvertent release of nuclear weapons, a regional nuclear conflict, nuclear proliferation, or the acquisition of nuclear weapons by terrorists. At the same time, the military utility of nuclear weapons for the United States has decreased dramatically. Russia, the successor to the Soviet Union, is no longer an adversary, and the United States, now the world's unchallenged conventional military power, can address almost all its military objectives by nonnuclear means. The only valid residual mission of U.S. nuclear weapons today is thus to deter others from using nuclear weapons. Given all this, it does not make sense for the United States to maintain a nuclear weapons stockpile of close to 10,000 warheads -- many of them set on hair-trigger alert -- and to continue to deploy nuclear weapons overseas.

An effective nuclear policy would take into account the limited present-day need for a nuclear arsenal as well as the military and political dangers associated with maintaining a massive stockpile. Building a new generation of warheads, as the Bush administration has proposed, would only compound these risks further.

Nuclear weapons cannot be uninvented, but as former Secretaries of State George Shultz and Henry Kissinger, former Defense Secretary William Perry, former Senator Sam Nunn, and the outgoing British foreign secretary, Margaret Beckett, have recently argued, a shift in U.S. policy could blaze the trail toward their eventual prohibition. Given that the risks posed by nuclear weapons far outweigh their benefits in today's world, the United States should lead a worldwide campaign to de-emphasize their role in international relations.


During the Cold War, the United States' policy of deterrence was designed to convince the Soviet Union's leaders that the assets they valued most highly, including their population, armed forces, and industrial centers, risked destruction if Moscow launched a major attack on the West. Estimates of the nuclear forces Washington needed to make such a threat credible -- that is, what forces it would need to be able to retaliate after withstanding a nuclear first strike -- differed widely. Some analysts were optimistic and thought a limited arsenal would suffice; others were pessimistic and sought to establish unchallengeable nuclear primacy. These debates, coupled with parochial bureaucratic pressures from the U.S. Air Force, led to a buildup of nuclear weapons that in retrospect appears inexcusable. Meanwhile, the Soviets escalated their forces as well. At the peak of the arms race, the United States and the Soviet Union combined held about 70,000 nuclear weapons (almost 30,000 remain today). The resulting stalemate was designated "mutual assured destruction" (MAD) and became a hallmark of the Cold War era.

In the end, the policy of nuclear deterrence worked (although I believe it would have succeeded with a more limited arsenal). The Soviet Union and its Warsaw Pact partners were contained, and a nuclear taboo evolved: U.S. and Soviet leaders realized that using nuclear weapons, whatever the immediate military advantages to be gained, would be a momentous decision. Having seen the results in Hiroshima and Nagasaki, they refrained from ever doing so. This was not the result of a general policy but rather a series of case-by-case decisions.

The world today is different, however, and it calls for a different approach.


The Bush administration has set out its nuclear weapons strategy under the same broad rubrics as the rest of its defense policy, arguing that it is designed to "assure allies and friends," "dissuade competitors," "deter aggressors," and "defeat enemies." The administration claims to have moved from the "threat-based approach" of the Cold War to a more flexible and forward-looking "capabilities-based approach." The old strategic triad of intercontinental ballistic missiles, bombers, and submarine-launched ballistic missiles is being supplemented by missile defense and a "responsive infrastructure" in the defense industry that can adapt swiftly to changing conditions. The problem is that this capabilities-based approach destroys a rational response to emerging threats. Rather than encouraging decision-makers to interpret the political context, judiciously measure the capability and intent of an adversary, and do what is necessary, it encourages them to respond to threats simply based on what they can do.

Unveiling the new policy in January 2002, J. D. Crouch, then the assistant secretary of defense for international security policy, argued that it was conceived "as a way for us to draw down the force ... [and reduce] dependence on nuclear weapons ... [while making] the nuclear force that we retained as safe, reliable, and effective as it can be." There has indeed been some retrenchment; the number of U.S. strategic warheads decreased from approximately 7,600 in 2002 to just over 5,200 in 2006. However, the total number of U.S. nuclear warheads, including those held in reserve, still hovers around the 10,000 mark. Moreover, despite the administration's rhetoric, the new approach is remarkably nonspecific. The administration's current policy provides little clear guidance on the deployment and readiness of nuclear forces; if pressed on these questions, officials generally say only that "all options are on the table." Even after the recent Bush-Putin talks in Kennebunkport, Maine, queries regarding future nuclear force levels have been answered with vague references to "the minimum level consistent with national security." Worse still, the notion that the Bush administration's broader defense strategy, which is known in shorthand as "assure, dissuade, deter, defeat," can be applied to nuclear policy is misguided and dangerous.


Assurance has always been a key element of U.S. nonproliferation policy: Washington has long let selected non-nuclear-weapons states know that it will unfold a protective umbrella over them in case of aggression. It has also complemented these positive security assurances with negative security assurances -- indicating that the United States will not use nuclear weapons against a non-nuclear-weapons state that is a party to the Nuclear Nonproliferation Treaty (NPT) unless that state assists a nuclear power in attacking the United States or one of its allies.

But given the greater number of smaller threats in the world today, the notion of assurance raises a host of difficult questions. To what extent does positive assurance require a nuclear umbrella at all? Should this umbrella open if an attack has not yet occurred but appears imminent or technically feasible? Should it cover nonnuclear attacks as well as nuclear ones? Officials in Washington often lace their answers to such questions with vague threats of a response by "all possible means," but in the context of U.S. nuclear dominance, such a reaction implies an overly broad and counterproductive interpretation of assurance. Instead, it would make more sense to adopt the narrowest interpretation of assurance, stating clearly that a U.S. nuclear response would only follow a nuclear attack on the United States or its allies.

The notion of dissuasion is even more problematic. The Bush administration's 2002 National Security Strategy states, "Our forces will be strong enough to dissuade potential adversaries from pursuing a military build-up in hopes of surpassing, or equaling, the power of the United States." Such a policy is debatable with reference to conventional forces, but when applied to nuclear weapons it is both dangerous and counterproductive. The United States' large nuclear arsenal does nothing to dissuade minor states from acquiring nuclear weapons; on the contrary, it only adds to their incentives to do so. Nuclear weapons have become the great equalizer: once a state acquires, or appears to have acquired, a small number of deliverable nuclear weapons, it can deter attacks itself and thus gains a substantial degree of political clout. Large U.S. military deployments, particularly of nuclear forces, thus do not dissuade potential adversaries from a military buildup -- they help persuade them to acquire nuclear weapons of their own.

Deterrence has not become obsolete in the wake of the Cold War, but with the demise of the United States' hostile relationship with the Soviet Union its implications are different. Deterring Russia, as well as China and other states that have acquired nuclear weapons, remains a justifiable function of U.S. nuclear weapons policy. But several thousand U.S. nuclear warheads are not needed to discharge that mission; a few hundred would suffice. No longer is there any justification for maintaining a vast arsenal to threaten a large number of targets in Russia. No longer is it necessary to keep thousands of strategic weapons on hair-trigger alert in order to respond to an unexpected attack. No longer is there a military necessity for having U.S. nuclear weapons in Europe when targets anywhere can be reached from the United States or from the oceans. Under the new threat environment, the same deterrent effect as before can be achieved with much smaller nuclear arsenals. Consequently, MAD does not have to be the necessary implication of a prudent deterrence policy in today's world.

Nor are large numbers of nuclear weapons needed to ward off potential nuclear threats from rogue states or nonstate actors. Some worry that proliferators such as Iran and North Korea may prove to be undeterrable. This is unlikely to be the case, since the leadership of even a rogue state can be expected to value its own survival. A dramatically reduced U.S. arsenal would still provide more than enough weapons to deter such a threat. Small and elusive nonstate actors, such as terrorist groups, meanwhile, having no fixed or independent home address, are not subject to the logic of nuclear deterrence. Whatever one thinks of the "war on terror," it would be hard to maintain that nuclear weapons should play any significant part in it.

The defeat concept, finally, implies that nuclear weapons remain a usable military tool for the United States in actual warfare. But beyond deterrence, these weapons serve no useful mission in this day and age. As President Ronald Reagan declared in 1985, "A nuclear war cannot be won and must never be fought." The notion of using nuclear weapons in combat against specific targets believed to be vulnerable only to nuclear attacks is as counterproductive today as it was during the Cold War. This strategy, known as "nuclear utilization target selection," has been aptly designated by the acronym "NUTS." Considering the United States' conventional weapons superiority, it deserves no role in U.S. policy.


At the same time that the Bush administration has pursued such misguided nuclear doctrines, it has allowed international nonproliferation efforts to wither. The nonproliferation regime codified by the NPT, which came into force in 1970, has indeed succeeded in encouraging many states with embryonic nuclear weapons programs to abandon them. However, the NPT is under severe stress today. Several non-nuclear-weapons states that are parties to the NPT appear to be striving for nuclear weapons status in contravention of their treaty obligations. Four states known to have nuclear weapons capabilities (Israel, India, Pakistan, and North Korea) remain outside the treaty altogether.

The existing nuclear weapons states, in general, and the United States, in particular, bear a substantial share of the responsibility for these disquieting developments. Washington has consistently disregarded its obligations under the NPT to minimize the role of nuclear weapons in international relations and to work in good faith toward their eventual elimination. The United States' effort to build and deploy a new, modernized arsenal -- exemplified by the Bush administration's proposal for a Reliable Replacement Warhead program, which would create a new generation of nuclear weapons deemed safer than their Cold War predecessors -- is the most recent example of such disregard. Rather than seizing the opportunity to limit the role of nuclear weapons, the current administration is searching for new nuclear missions with narrow military goals.

The weakening of the nonproliferation regime is not in the interest of the United States and is a menace to global stability. The risk that a terrorist group will acquire nuclear weapons is real and terrifying, and to minimize that risk Washington must revise its policies and increase its commitment to multilateral nonproliferation initiatives. Until now, the United States' counterproliferation policy has been characterized by selective enforcement. Through its Proliferation Security Initiative, the Bush administration has essentially relied on a "coalition of the willing" to interdict sensitive shipments by nations designated as unfriendly and impose sanctions on selected non-nuclear-weapons states pursuing indigenous atomic energy programs. For instance, the United States condemns Iran's fledgling uranium-enrichment activities while condoning very similar activities by Brazil. Such selective enforcement is counterproductive, since the NPT gives non-nuclear-weapons states an "inalienable right" to pursue nuclear power for peaceful purposes. Uranium-enrichment and plutonium-reprocessing technology can be used to achieve both peaceful and military objectives, the latter by shortening the lead-time needed to acquire nuclear weapons if and when states decide to do so. Therefore, these activities always pose a proliferation risk.

Guaranteeing a supply of nuclear fuel to non-nuclear-weapons states would reduce this risk. Access to an assured supply of fuel for peaceful nuclear power initiatives would remove any justifiable motive for states to acquire indigenous enrichment and reprocessing facilities. But providing such a fuel supply while inhibiting countries from developing dual-use elements of the nuclear fuel cycle would require international or multinational ownership of nuclear fuel stockpiles with strong safeguards against diversion to rogue states or terrorist groups. The indigenous production of all forms of plutonium and highly enriched uranium would have to be suspended pending the establishment of such a regime. Only a broad international approach that does not discriminate between "good states" and "bad states" can secure each state's "inalienable right" to develop nuclear power for peaceful purposes without increasing the risk of proliferation.

In addition to ending the practice of selective enforcement and creating a centralized supply of nuclear fuel, a number of other measures will be required to reduce the risk that terrorists might acquire nuclear weapons or materials. The protection of existing stores of weapons and nuclear materials needs to be upgraded, and the stockpiles themselves need to be reduced dramatically. Intelligence and homeland security bureaucracies need to make the detection and interdiction of nuclear materials in transport an even higher priority. Unfortunately, the effective remote detection of weapons-grade radioactive material remains a scientific impossibility because the radioactivity of plutonium and highly enriched uranium is weak and can be shielded. Therefore, interdiction efforts must rely instead on high-quality intelligence and rigorous physical searches at borders and cargo terminals.

Finally, all parties to the NPT should be required to subscribe to the International Atomic Energy Agency's Additional Protocol, which allows the agency to conduct more comprehensive and frequent inspections of declared and undeclared nuclear facilities than provided for under the current minimum protocols. At the same time, states that opt to withdraw from the NPT should be deemed a threat to international peace and security and referred to the UN Security Council, which could then take action against them.


Policymakers crafting a new nuclear posture need to start their deliberations by considering the extremely limited number of justifiable uses for nuclear weapons today and the grave risks and costs generated by the maintenance and improvement of vast nuclear arsenals. If they do so, they will conclude that the United States can reduce its nuclear stockpile substantially while still maintaining a strong enough deterrent to prevent the use of nuclear weapons against the United States or its allies.

Going beyond the loose commitments they have made to date, Washington and Moscow should urgently negotiate further cutbacks in their nuclear arsenals, including tactical and reserve weapons, and codify these reductions in a formal treaty. Failing that, each country should take unilateral steps to reduce its arsenal. In the meantime, Washington should withdraw all U.S. nuclear forces from Europe and de-alert its deployed strategic nuclear forces, thus sending an unequivocal signal to Moscow that it is serious about nuclear disarmament.

Similarly, Washington would send an important message by adhering to the Comprehensive Test Ban Treaty. Washington's insistence on maintaining its prerogative to test new weapons and its refusal to ratify the CTBT have been major obstacles to the treaty's coming into force and a continued blow to the world's nuclear nonproliferation efforts. The purely technical leverage of the CTBT is limited: modern technology allows states to develop and deploy safer and more reliable nuclear weapons without testing them in advance. But stopping nuclear tests, which the CTBT mandates, would make it harder to upgrade nuclear arsenals and would prevent non-nuclear-weapons states from developing any but the most primitive weapons. Accordingly, U.S. ratification of the CTBT would be an important political step forward.

The United States is faced with many decisions concerning nuclear weapons development, acquisition, and deployment as well as the reliability and readiness of its current stockpile. These decisions should be guided by a risk-benefit analysis of nuclear weapons policy. Since the Cold War, the risk-to-benefit ratio of nuclear weapons has grown dramatically. Maintaining a U.S. nuclear arsenal presents only one benefit today: deterring the use of nuclear weapons by others. Thus, there is simply no reason for nuclear weapons to play a central role in U.S. defense policy any longer. On the other hand, there is good reason for Washington to commit to a major nuclear rollback and to strengthening multilateral nonproliferation initiatives: doing so would demonstrate that it is serious about minimizing the role of nuclear weapons both at home and abroad. These moves would greatly enhance the national security of the United States.

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  • Wolfgang K. H. Panofsky is a particle physicist and Director Emeritus of the Stanford Linear Accelerator Center. He worked on the Manhattan Project from 1943 to 1945 and served as a Science Policy Adviser to Presidents Dwight Eisenhower, John F. Kennedy, and Jimmy Carter.
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