Nuclear weapons are overrated. They are no magic talisman that, by simple possession, can guarantee the survival of a regime. After all, the Soviet Union, the world's second-largest nuclear power, lost not only its sphere of influence, but ultimately its very existence as a sovereign nation. Currently, Israel, the world's sixth nuclear power, is locked in a protracted struggle with the Palestinians, a conflict with the most serious economic, political and psychological implications for Israel's fundamental sense of national security--and the possession of nuclear weapons makes not one iota of difference. Nor do nuclear weapons give a state any advantage in dealing with other foreign policy challenges. The United States experienced more than 50,000 fatalities and a searing defeat in Vietnam while possessing tens of thousands of nuclear weapons that were useless white elephants in dealing with the Viet Cong. The same might be said of biological and chemical weapons.

But the weapons should not be belittled; their destructive capacity deserves respect. And they continue to be viewed by many states as the great equalizer in international affairs. India, for example, began to develop nuclear weapons after its defeat by China in 1962. Pakistan followed suit after its defeat by India in 1971, and North Korea appears to have initiated its program after losing its nuclear-armed protector, the USSR, in 1991.

We no longer live in an era where the technologies needed to craft weapons of mass destruction (WMD) are the preserve of a few major powers and where state actors alone have a bearing on international affairs. The moratorium on the use of nuclear weapons--which has lasted more than sixty years, an extraordinary amount of time given the expectations in 1945--may be drawing to a close. In the early years of the 21st century, the WMD business already resembles an imperfect free market, with eight known nuclear players and two more in the wings. Biological and chemical weapons are experiencing their own renaissance. Some of the newer entrants, not to mention apocalyptic terrorist groups, may be far more difficult to deter from using such weapons than the established powers have been.

President George W. Bush has made reversing the proliferation of WMD a central element of his foreign policy. Pre-emptive actions to forestall hostile acts by rogue states and terrorist groups were a leitmotif of his first term, which, among other things, can claim credit for the removal of Saddam Hussein as a potential proliferator, for Libya's disarmament and for the successful establishment of the Proliferation Security Initiative (PSI). However, far more is required before the president can claim success, including progress on the tough cases of Iran and North Korea.

The president's second four-year mandate offers a unique opportunity to realize the laudable goals declared during his first term. This time, however, half measures will not suffice. Time is running out, and the United States cannot afford to let the current diplomatic hiatus regarding Iran and North Korea drag on indefinitely. Without major and prompt changes in the administration's approach to these two nations' nuclear ambitions, there will be ten nuclear powers on the world stage when President Bush leaves office, and the most recent entrants to the nuclear club will be the most dangerous.

In June 2004, the Bush Administration announced that the United States would cut its stockpile of nuclear weapons by nearly one-half over the next eight years, reaching its lowest level in several decades. Operationally deployed nuclear weapons would be reduced from more than 6,000 when President Bush took office to between 1,700 and 2,200 by the year 2012. The total stockpile would be similarly reduced, from more than 10,000 in 2001 to about 6,000 in 2012. This capstone of a long series of actions by President Bush made good on his 2000 campaign pledge to rely less on nuclear weapons in U.S. national security policy and to reduce U.S. nuclear forces accordingly.

The administration's 2001 examination of nuclear plans and policies, called the Nuclear Posture Review, had been informed by a similar view, as were subsequent decisions. Throughout his first term, the president acted fairly consistently to de-emphasize the role of nuclear capabilities in U.S. national security policy and to diminish their prominence in international relationships around the globe. More significantly, other types of military capabilities started supplanting nuclear weapons in U.S. strategic doctrine. Missile defenses, for example, were elevated as an equal leg of U.S. strategic capabilities. According to the new policy, the United States would rely less on threats of massive destruction in retaliation for an attack and more on the projected capabilities of modern defense systems to deny an enemy the ability to attack the U.S. homeland. In addition, the administration stated that long-range, precisely targeted conventional munitions would be substituted for nuclear weapons in some missions. Indeed, judging by the rhetoric of Bush Administration officials, conventional-weapon options are clearly preferred in most situations.

Finally, the administration put more teeth into efforts to stem and reverse WMD proliferation, utilizing secret diplomacy to negotiate the termination of Libya's nuclear program, covert actions to intercept shipments of nuclear components, and the very public Proliferation Security Initiative to enlist other nations in cooperative action to intercept shipments of WMD-related materials.

During the first term, however, the Bush Administration sent contradictory signals to both existing nuclear powers and would-be proliferators by arguing for the need to examine new low-yield nuclear weapons, including so-called "bunker busters", and by emphasizing pre-emption as the centerpiece of its counter-proliferation policy. Admittedly, the administration's "National Strategy to Combat Weapons of Mass Destruction", released in December 2002, made reference both to counter-proliferation against the use of WMD and to strengthened non-proliferation efforts to prevent states and terrorists from acquiring WMD materials. But the latter part of the strategy--by nature a multilateral approach--was belied by the administration's tough approach to North Korea and Iran, and by the apparent unilateralism that seemed to dominate the administration's approach to international affairs during the first term. Similarly, the counter-proliferation objective was overshadowed by other competing administration goals, particularly the need to gain international cooperation on the War on Terror. Post-9/11 policy toward Pakistan, including a seemingly permissive attitude toward President Pervez Musharraf's protection of A. Q. Khan and the subsequent failure to extract much information about his nuclear proliferation network, is a case in point.

Undoubtedly, the most serious gamble in recent U.S. policy involves Iran and North Korea. The administration's unwillingness to deal directly with these countries has allowed them more time to develop nuclear programs, to the point where North Korea is probably already a nuclear power and is most unlikely to be persuaded to give up its current arsenal. There may still be time to prevent Iran's ascent to nuclear-power status, but the administration's refusal to talk directly with Iranian officials continues to hamper its ability to strike a deal. Coming from the world's most powerful nation, this policy of refusing to talk directly with repugnant regimes is counter-productive. It assumes one of two positions: that the United States can live securely in a world in which hostile states like North Korea, Iran and possibly others have nuclear weapons; or that third nations can deal effectively on America's behalf with the regimes in Pyongyang and Tehran. Neither is likely to be true.

Though the administration articulated the right policy and registered some early successes, it now faces the near-term possibility of two major failures. Should both Iran and North Korea join the club of nuclear powers, additional proliferators are certain to follow, with Saudi Arabia and Japan as the most likely candidates in the first round. If it is serious about containing and reversing WMD proliferation, the Bush Administration should extend, deepen and accelerate implementation of the policies put in place during the previous four years.

Are Nuclear Weapons Useless?

There are two prevailing scenarios when assessing the threat posed to the United States by WMD-armed actors. The first, and the one that has received the most attention since the September 11 attacks, involves the risk of terrorist groups acquiring WMD materials and using them against either the U.S. homeland or U.S. forces and interests overseas. The second scenario concerns WMD-armed countries with hostile intent. The threat envisioned would typically be an attack by a relatively weak but WMD-armed hostile nation on the homeland, on forces deployed overseas or on an ally.

What action might be taken against such WMD threats? In the case of suicide terrorists (or a suicidal leader), U.S. military capabilities--including America's nuclear arsenal--cannot serve as effective deterrents; threats of punishment will never dissuade people willing to sacrifice their lives in suicide missions. By definition, then, U.S. capabilities can only have military utility: either to pre-empt and destroy such threats--assuming they can be identified before their deployment and use--or to defend against them once an attack is underway. Against a small, WMD-armed power, deterrence might work, and even the overwhelming conventional U.S. military capabilities might be powerful enough to prevent hostile action.

In either case, what would be needed to defend the United States and U.S. interests would be: brilliant intelligence (probably the most important element); an effective, integrated command-and-control system that has been well planned and rehearsed (as the time available for action is likely to be very short); long-range and prompt means of delivery; small numbers of flexible, precise and effective conventional weapons; and adequate protection for the homeland and for U.S. forces deployed abroad. This last element includes not only developing an effective missile defense system, but putting into place a comprehensive set of defensive measures against threats to the U.S. homeland. Overcoming the Defense Department's lingering reluctance to allocate resources to this function is necessary to ensure that America is better prepared to face an unconventional attack the next time it occurs.

In going after terrorist groups or rogue states armed with or seeking to acquire nuclear, biological or chemical weapons, conventional forces remain the United States' most effective tool. These forces include special operations units, precision-guided conventional munitions tailored to penetrate or disable underground facilities and destroy the special weapons within them, and the means of promptly delivering such capabilities anywhere in the world.

Using nuclear weapons against these types of threats might be militarily feasible, but it seems very unlikely that any U.S. president would decide to authorize a nuclear strike to pre-empt a suspected terrorist threat or an assault from a WMD-armed power. In theory, if the president believed an attack on the homeland were imminent and likely to be devastating, he might consider a pre-emptive use of a nuclear weapon. In reality, however, the likely uncertainty of any intelligence on the threat, the availability of alternative military actions, the prospect of large losses of innocent lives, and the enormous political ramifications of the first use of a nuclear weapon since Nagasaki would make any president extremely reluctant to take such a step. This is why it is so important to develop long-range conventional weapon systems that could be used to respond promptly to a WMD threat. Even in response to an enemy's first use of nuclear weapons, say, in an Iran-versus-Israel scenario, the ability to respond conventionally and win should be rated higher than the ability to retaliate with nuclear weapons.

One argument put forth in favor of developing new low-yield nuclear weapons is that the fewer innocent casualties likely to result from their use would dampen this self-deterrence. When one examines how presidential-level decisions are made, however, the specific characteristics of the nuclear weapon to be used are unlikely to make a difference. Of primary political significance would be the decision to use a nuclear weapon; questions of yield and the specific forecast of casualties would be lost in the weeds.

The only powerful argument for developing new types of nuclear weapons is their potential to penetrate deeply buried facilities that lie outside the destructive reach of current U.S. conventional capabilities. This argument justifies continuing research on these and alternative means to neutralize hard and deeply buried targets. Any decision on the full development of such capabilities, however, should await the results of more serious research efforts than have been possible to date.

Even so, it should be recognized that any U.S. program to develop new types of nuclear weapons undercuts the president's proclaimed goal to stem and reverse WMD proliferation, and their potential military utility thus has to be weighed against the negative consequences of such a decision for the fight against proliferation. When the United States asserts a national security need to acquire new types of nuclear capabilities, while at the same time continuing to maintain large, if declining, nuclear stockpiles from the Cold War era, the diplomatic power of its demand that others abstain from or even give up nuclear capabilities is greatly weakened.

There is also an argument that researching new types of nuclear capabilities diverts resources from more relevant military capabilities. But the cost of the nuclear weapons research currently on the table is chump change by weapon-system standards. A more relevant economic question concerns nuclear delivery systems. Programs are ongoing both to improve existing land-based Minuteman ICBMs and sea-based Trident ICBMs, and to begin developing successors to them. The real spending will begin as these latter programs move into more advanced development. Just when that should happen, and whether there might not be alternatives to current thinking on them, are questions that should receive high-level attention in the Department of Defense and Congress.

Missile Defense and the Great Powers

There is also a third threat scenario involving the use of WMD: the emergence, down the line, of a hostile great power that would challenge the United States. The only such potential rivals in the foreseeable future are a back-sliding Russia and an openly confrontational China, perhaps even aligned with one another.

It goes without saying that the United States should pursue diplomatic, political and economic strategies to reassure these nations that we do not intend them any harm and that they will derive benefits from cooperative relations with us. But it is only prudent for the United States also to maintain a veiled military posture that makes clear to them that attempting to compete militarily with the United States would entail enormous costs and no success. This is essentially the strategy the Reagan Administration pursued when it threw billions of dollars into defense programs to compel the Soviet Union to give up the competition.

Current U.S. efforts to develop a missile defense system have raised repeated skepticism as to its feasibility, cost and ultimate use. From a technical point of view, it is no doubt feasible to develop at a reasonable cost a highly reliable missile defense system that can protect the country against small numbers--say, tens--of incoming missile warheads. Granted, there have been test failures and operational problems over the past year. But this is to be expected in any new system development and is primarily an engineering challenge, not a question of the program's viability or practical utility. The cost and time required to develop a defense system that can reliably defeat a more extensive threat--say, a few hundred warheads--is more problematic. Effective protection against a threat of this magnitude would require the interception of hostile missiles during the boost phase of their flight, a technology that is less well known and more difficult to master, and may cost more than the nation is willing to spend on this type of threat. Rationally, in the mid-term it might make more sense to continue to depend on deterrence against the types of threats that could be posed by Russia and China--imperfect though deterrence may be--and to allocate more resources instead to protecting the country against terrorists and rogue states.

The challenges of developing a missile defense system are also politically critical. More specifically, in the case of Russia--the only potentially hostile country still possessing a large nuclear force and extensive nuclear infrastructure--U.S. strategy should make clear that no missile defense we could conceivably deploy for decades would jeopardize Russian retaliatory capabilities. Negotiations with Russia on continuing mutual nuclear force reductions got off to a good start during the first Bush term and should be pursued further. So long as Russia retains confidence in its own deterrent capability, cooperation can continue without the need for a new arms control treaty.

China, on the other hand, with its still-limited long-range nuclear forces and only rudimentary technology and infrastructure, calls for a different approach. The United States currently has the means to deny China a retaliatory capability, meaning a capability to deter the United States from acting in defense of its interests in regions close to China's shores. It is essential that the United States retain its freedom of action. The short-lived 1995 crisis over Taiwan, for example, was resolved in part through diplomatic efforts and mutual realization that each side had much to lose from continued tensions, but also because U.S. military activities in the region indicated a willingness to intervene.

In a scenario ten to twenty years from now in which China already possesses a significant long-range nuclear arsenal and the capability to strike the U.S. homeland, its willingness to compromise might be less pronounced. In such circumstances, Chinese leaders might conclude that given the centrality of the Taiwan issue to them and its marginality in U.S. calculations, Washington would wish to avoid escalation to a nuclear exchange. As a result, for the next ten years at least, the United States may wish to maintain a substantial lead in offensive capabilities vis-Ã--vis the Chinese, while building defenses capable of stopping the relatively small long-range force that China is likely to deploy during this period.

In considering the U.S.-China strategic relationship, it is also important to look at the question of nuclear testing. Since 1945, the United States has conducted some 1,030 nuclear tests, more than all other nuclear-armed nations combined. China has conducted only 45. As a result, the United States holds a considerable technological edge over its potential rival. Having already hit the flat part of the learning curve on nuclear technology, the United States has little to benefit from additional tests in terms of new capabilities, unlike China, which still has a lot to learn. In this context, it is essential for the United States to avoid giving China a pretext to advance its nuclear weapon designs and gain new capabilities by breaking the more than ten-year-old moratorium on nuclear testing. China may well break the moratorium on its own, but we should studiously avoid giving it an excuse to do so.

Strengthening Supply-Side Restraints

Finally, any effective U.S. strategy to contain and reverse WMD proliferation must place greater emphasis on the supply side of the WMD equation. Pre-emption and interception are by themselves insufficient; they must go together with effective preventive diplomacy. This is particularly true in the case of terrorist groups, given the difficulties in finding and deterring them. The administration should take advantage of the existing bipartisan support behind the 1991 Nunn-Lugar Act and the Comprehensive Threat Reduction program, aimed at securing Russia's vast stocks of WMD materials, to improve upon and further expand present initiatives. The 2002 G-8 non-proliferation initiative pledging $20 billion over ten years for Russia and other former Soviet states is one recent example of how U.S. leadership can promote multilateral cooperation in this field.

Our efforts to contain and reverse WMD proliferation should also involve putting real resources--diplomatic as well as financial--into existing multinational agreements and institutions. The United States should actively support the International Atomic Energy Agency in its role of verifying that non-nuclear states do not misuse their civilian technologies to advance nuclear weapons projects, while at the same time providing credible reassurances to would-be and existing proliferators that a willingness to share information openly or dismantle existing arsenals will be rewarded. The United States must also ensure that the ongoing Non-Proliferation Treaty review conference later this year is a success. Two other equally important multilateral treaties requiring the attention and leadership of the United States are the 1972 Biological and Toxin Weapons Convention, which is due for renewal in 2006, and the 1997 Chemical Weapons Convention, whose mandate to gradually eradicate all declared chemical weapons and facilities has already met with various delays.

Finally, it is time to rescue the much-maligned Comprehensive Test Ban Treaty from its current limbo and bestow real legitimacy on it by seeking to reverse the negative Senate vote of 1999. Some 120 of the total 175 signatory countries, including three of the five original nuclear weapon states, have already ratified it. An administration decision to resubmit the treaty for Senate approval would send a powerful message that President Bush is as serious about making the United States and the world safe from weapons of mass destruction as he is about fighting the global War on Terror.

Some argue against the test ban on the grounds that the United States may eventually have to test to ensure the reliability of its remaining nuclear warheads. But alternatives to explosive testing exist, including the current efforts exerted as part of the stockpile stewardship program. Moreover, by replacing current warheads that were designed with advanced capabilities and very narrow tolerances with smaller numbers of less sophisticated warheads designed for reliability, the United States can ensure--without nuclear testing--the continuing viability of its nuclear weapons in the narrow roles they could play in the nation's security.

There is no greater long-term threat to the United States than the prospect of a WMD attack. This administration has repeatedly drawn attention to this truly important issue, but more needs to be done. As a first step, the United States should make the fight against WMD proliferation an integral part of its relations with all foreign countries. It should seek to influence other countries' WMD policies through pressure and appropriate rewards. It is a matter of priorities. Every U.S. administration since Jimmy Carter has turned a blind eye to Pakistan's efforts to develop nuclear weapons and its truly evil black market trade in nuclear technology and materials. We are now paying the price for these decisions in both Iran and North Korea, and they may prove to be the most severe threats ever posed to U.S. security.

The historical record makes clear that nuclear weapons favor the weak. Given that the United States is currently the world's dominant military power and seems likely to remain so for the foreseeable future, it should do all within its powers to reduce the perceived utility of weapons of mass destruction, to contain and roll back their spread, and eventually to eliminate all such weapons. Anything less would be irresponsible and potentially catastrophic.