Of the three interwoven threats to America--terrorists, rogue states and the proliferation of WMD--the third has provoked the least public debate since 9/11. This is curious, since the invasion of Iraq was intended as an exercise in counter-proliferation and the administration has announced a major program to deal with other cases of the spread of WMD. But public debate has focused on the prudence of pre-emptive war and unilateralism, and on whether Iraq had stockpiled WMD in the first place, not on the ways the momentum can be and is being used to overcome further WMD threats in Libya and Pakistan and to strengthen the anti-proliferation regime more generally. The Bush Administration's ongoing program has received little serious attention outside of expert circles, despite eye-catching measures such as the Proliferation Security Initiative, which empowers the United States to board ships suspected of carrying WMD contraband.

Meanwhile Iran and North Korea demonstrate that the old non-proliferation regime is still in crisis. Yet at the same time, wider diplomatic conditions are better than at any point since the 1940s for a realistic policy of not only non- but even counter-proliferation--that is, the use of force to stop proliferation. Measures can be taken in the near future to reverse the impending crisis, and a short capsule history will explain why.

The history of non-proliferation diplomacy falls into three periods. The first was the period of U.S. nuclear monopoly that lasted from 1945 to 1949, during which robust plans for an anti-proliferation regime were proposed. In the late 1940s, the Baruch Plan proposed global management of uranium and UN enforcement actions that would have been exempt from a veto in the Security Council.

It was no accident that the Baruch Plan was drawn up at a time when there was a single power center on nuclear affairs--the United States--even though it avoided drawing on American power per se. A single cohesive global power center, pushing through standards and taking the steps necessary to enforce them, was needed if proliferation was to be prevented. Baruch was a proliferation pre-emption plan. Yet the Baruch Plan was stymied by the Soviets, who exercised their Security Council veto to avoid adopting the plan, thereby preserving the principle of Security Council veto in all matters, including the question of nuclear proliferation, which the Baruch Plan would have abolished. Thus it was doomed from the start.

Two different Western thinkers saw the logical next step. Bertrand Russell and James Burnham both advocated the preservation of America's nuclear monopoly by a preventive war threat against the USSR if it sought to build the bomb. Both saw U.S. power as the only available enforcement arm for non-proliferation. As the phrase went at the time, it was a matter of "using the atomic monopoly in order to preserve the atomic monopoly."

Realistic though this sounded, it was hugely risky. Preventive war was threatened not against a small rogue state but against one of the two surviving great powers--risking a world war with an uncertain outcome. Most non-communist countries were in ruins, revolutionary communism was a global force, and Soviet authority was buttressed by its decisive role in winning World War II. Though Russell and Burnham hoped to win by threat of war, the threat, to be convincing, would require a clear capacity to win.

Aware of these difficulties, Russell and Burnham iterated a political prerequisite for their policy: a union of the remaining free countries of Europe with America. This would provide a wider power base for victory and for subsequent stabilization. It would also serve legitimizing purposes, fitting the pre-emptive policy into the progress of world order: a united Europe-America already constituting, in Einstein's phrase, a partial world government. In short, it mixed the ideas of global empire and world government in a relatively realistic manner, setting up the main elements in embryonic form and dealing with imminent technological dangers.

But the Russell-Burnham policy ended along with American nuclear monopoly. The Soviet Union acquired the bomb in 1949. When Stalin died in 1953, the result was an immediate switch in Soviet diplomacy that brought the Korean War to an end and set the Cold War on more stable lines. Russell and Burnham then went their separate ways. Russell put his priority on nuclear disarmament and constructing neutral bridges back to a unified world; Burnham, on defeating communism to secure a Western-led world order. Russell became the grandfather of the New Left, Burnham, of the neoconservatives. Nuclear bipolarity had become an established fact; preventing further proliferation now became the main task of diplomacy.

The second period of non-proliferation, lasting from 1949 to 1989, was marked by the fact that there was no single power center capable of enforcing the rules. In the early 1960s, John Strachey, an anti-communist British Labour politician and strategist, called on America and the Soviet Union to constitute such a power center together and to enforce tough inspections--through preventive war if necessary. As with the Baruch Plan, however, Cold War rivalry prevented the Strachey Plan from getting off the ground.

To be sure, Mao accused the two superpowers of conducting a Strachey-like global "condominium" or "co-imperium." This was what he thought any two rational superpowers would do. (In the 1940s, the Soviets had similarly accused America of following the Russell-Burnham policy. They too thought any rational power would do this.) The reality was that America and the Soviet Union were in deadly competition for global power, even as they wished to cooperate on proliferation. So the standards were set--and set low--by negotiations among enemies. The result was an "international regime" whose workings were structured to slow proliferation rather than to halt or reverse it.

In the 1950s, the IAEA was founded to promote peaceful uses of atomic energy and to provide economic incentives for its non-military use. It soon became unclear whether this was restraining proliferation or promoting it. In the 1960s, the two superpowers took something from the Strachey proposal: They acknowledged a joint responsibility for non-proliferation and the management of the arms race, negotiated the Partial Nuclear Test Ban Treaty in 1963, and played a leading role in creating the Nuclear Non-Proliferation Treaty (NPT). This upgraded the IAEA's authority to conduct inspections in each signatory country, with a goal of providing enough transparency and confidence as to avert races for the bomb among mutually suspicious groups of countries. It also strengthened Russia's embryonic westward orientation, in contradistinction to China.

During the same period, having created an alliance system within the West designed, among other things, to limit proliferation, the United States proposed a specific roll-back in the 1960s: a Multilateral Nuclear Force for NATO. This would have integrated French and British nuclear forces with America's and provided a potential core for an ultimate reversion to unity of nuclear forces worldwide. Charles de Gaulle vetoed the idea, however, preferring an independent nuclear deterrent for France. Some Gaullist strategists argued that global proliferation would lead to stability--a view shared by Maoist China and Castroite Cuba and later taken up by the likes of Kenneth Waltz and, of course, by subsequent generations of rogue states.

Thus, while proliferation was not reversed, neither was it allowed to spread unchecked. The NPT-IAEA regime provided regular mechanisms to slow down proliferation while making further proliferation among its signatories illegal--except for the loophole that the treaty could be renounced (as North Korea has recently done). It divided signatories into those acceding as nuclear states and those acceding as non-nuclear states. It perpetuated the discrimination in their status already established. And it enlisted the self-interest of the established nuclear powers in protecting the importance of their nuclear status by limiting the size of their club.

Great Power Responsibilities

It must be emphasized here that the NPT regime reflected and built upon the traditional conception of the special responsibilities of great powers, which goes back at least to the Treaty of Westphalia. The great powers mutually attributed special rights and duties to one another. The small powers accepted the reality, as well as the unwritten prerogative of the great powers to amend occasionally the rules in order to preserve the system's fundamental principles. Indeed, international law was largely the creature of great power practice.

The responsibilities of the great powers naturally grew more urgent with the advent of nuclear weapons. Five powers were formally attributed special rights in the Security Council and given almost unlimited authority to do as they chose--when unanimous--in the name of preserving international peace and security. Other states, accepting the brutal lessons of the two world wars, legally endorsed this extraordinary abrogation of their sovereignty and ratified the UN Charter. Yet when the Cold War broke out, and as long as the Security Council remained divided, the great-power prerogatives were recognized informally as belonging unilaterally to the superpowers. It was the only possible basis for successful non-proliferation.

Yet this was a realpolitik that dared not speak its name. Both superpowers were formally committed to anti-imperialist ideologies derived from their respective revolutions. They took this seriously enough to cooperate symbiotically in ending Europe's overseas empires. They competed for the loyalty of these ex-colonies and knew no greater accusation to hurl at each other than "imperialist." It would have been hard for them to jointly discuss such an imperialist subject as forceful counter-proliferation.

As long as the Cold War continued, the superpowers were enemies competing for clients, not allies forming a cohesive anti-proliferation core. The reality of competition repeatedly trumped the need for cooperation. Any nuclear-seeking regime would lean to one or the other side, so a preventive attack on it would change the strategic balance between the superpowers. It would have required something close to a miracle to get the superpowers to agree on mutually compensatory terms for proceeding with such a proposed attack. For example, the Soviets reportedly suggested a joint pre-emptive attack on China in 1969 and 1970; the United States refused, exploiting the situation instead to form its own links with China against the USSR.

The Third Phase

Today the Cold War is over--and the third phase of non-proliferation is unfolding before our eyes.

Its most important features are the abatement of Soviet-American mutual hostility; the replacement of bipolarity with unipolarity (allowing tighter multilateral negotiations and more effective enforcement); and the substitution of small states for great powers as the potential targets of counter-proliferation. At the same time, the urgency of curbing proliferation has also grown. Nuclear knowledge and material are spreading, and rogue regimes and Islamist terrorists are actively seeking to acquire them.

But standards, once lowered, are not easy to raise again. A major jolt was needed to send them back upward. The Iraq War supplied the jolt. Libya, a long-intractable case, finally moved to renounce its nuclear (and great power) ambitions. Diplomacy alone would not have achieved this.

Nor would war alone have sufficed. In fact, the Gulf War already supplied an appropriate jolt in 1991, but that opening was not sufficiently exploited. With the Cold War drawing to a close and the trend toward cohesion on the Security Council growing, there could have been a joint Russian-American-led effort to clean up the rubbish they had strewn around during the Cold War. The moral energy was available for a new post-Cold War partnership. Global opinion would have welcomed almost anything that could have been presented as getting rid of "Cold War relics." But it was not to be.

The Gulf War revealed the holes in the old IAEA inspections regime. It led to creation of a new and more intrusive regime of inspection (UNSCOM, for the special case of Iraq). It introduced further discrimination into non-proliferation policy. It applied not to everyone but to a specific known offender. It was asymmetrical. It was put in the terms of truce for a defeated small country, thus perpetuating the war's abridgement of Iraq's sovereignty, and it was applied on that country by the Security Council making use of its unique legal authority over all other states. This enabled UNSCOM to be unusually successful in uncovering and destroying Iraq's WMD programs--although only with the help of further Anglo-American bombings and high-level defectors.

As time passed, the disunity of the Security Council and new forms of great- power rivalry came back into play. The Security Council's unit-veto structure made it ill-suited for carrying out a complex and costly program consistently, for states came to view their respective national interests differently.

In a sense, UNSCOM was too discriminatory. Remedial anti-proliferation was needed in more places than Iraq. Discrimination needed to be raised to the level of a norm applied to all nuclear-seeking rogue states. Several countries grew tired of enforcing the sanctions regime against Iraq in the course of the 1990s. As the UNSCOM regime applied only to a single case, it had differential impact on the great powers of the Security Council. The Iraqi government was able to play upon this, as well as upon resentment of America as the de facto leader and arbiter of the process that the Security Council and UNSCOM were in effect fronting.

Had an UNSCOM-type regime been extended to all the "states of concern", it would have aimed to curb proliferation globally and thus brought the national interests of great powers closer together. It would have recognized, for example, Russia's list of states of concern--Pakistan, Afghanistan, Saudi Arabia--a list whose validity the United States came belatedly to recognize after 9/11--alongside Iraq, Iran, Syria, Sudan, Libya and North Korea on the American list. Such bargaining could have made for mutual support in dealing with both sets of rogue states, instead of inspiring Russia to launch resentful polemics against America's unilateral decisions on which countries counted as "rogues."

But this was not done in the 1990s. The decade passed. The problems grew worse.

Today, as in 1991, we can afford neither diplomacy without war nor war without diplomacy. Where there has been significant success, it is because the coercive action on Iraq has been supplemented with semi-coercive diplomacy, and because that coercive diplomacy has supplemented the work of multilateral treaties and institutions. And there are signs that the United States--despite its alleged propensity to "unilateralism"--has taken these lessons to heart.

President Bush announced a six-pronged initiative to strengthen the NPT regime in February 2004. Taken together, its six points add up to a substantial strengthening of the non-proliferation system. It combines recent ad hoc efforts such as the Proliferation Security Initiative. It tacks on multilateral measures such as the "additional protocol" with the IAEA, which can be agreed to one country at a time, and it joins them to a series of unilateral measures and voluntary collective measures (through the forty-nation Nuclear Suppliers Group). Thanks to this realistic mesh of different levels of work, progress can be made before all countries have signed on--a reality that actually provides an incentive for countries to sign on. It is also realistically discriminatory--indeed, it creates a third tier in the nuclear hierarchy: countries that do not enrich uranium. It does not go nearly as far as the salto mortale Baruch Plan, but it could be described as its partial revival, adapted in light of the realities of the intervening half-century.

The six points received immediate endorsements from men like Mohamed ElBaradei, Director of the IAEA, and from the administration's inveterate critic at the Carnegie Endowment, Joseph Cirincione. The endorsements indicate a broad base of support for follow-through. At the same time, Cirincione called for greater balance between non-proliferation spending (very small), counter-proliferation spending (huge, counting Iraq), and consequence management spending (huge also, in ballistic missile defense and Homeland Security). This is a useful conceptualization. It suggests that a more full-service approach would help in consolidating elite support for the administration's counter-proliferation innovations. Carnegie has also put forth its own collective draft plan, entitled, Universal Compliance: A Strategy for Nuclear Security, for following up on the anti-proliferation momentum. It calls for taking the successful UNSCOM-UNMOVIC experience of intrusive inspections and extending it to other countries. It acknowledges that the threat of military coercion has been necessary for these successes. It draws heavily on the supranational rights of the Security Council to impose non-proliferation obligations on all countries, urging the use of this to prohibit withdrawal from the NPT and make its norms binding on all. It offers a comprehensive "strategy synthesiz[ing] some innovative approaches of the George W. Bush administration, the benefits of the traditional treaty-based regime, and many new elements."

Both sides of the debate thus agree that more should be done to generalize the recent advances based on war, threat and intrusive inspections. The degree of consensus is encouraging, as was the momentum of action after the Iraq War. Without it, the jolt of the 2003 war could have been mostly wasted, as was the jolt of the 1991 war.

If there is to be an effective and durable non- and counter-proliferation effort, diplomatic gains must be embedded permanently in agreements and institutions. Existing organizations have to be reinforced and supplemented where necessary. Skeptics will point out that such bodies can become obstacles to action--as the United States feared was true in the run up to the Iraq War. Such fears are not always wrong. When an international body is crippled by great-power rivalry, it is not scandalous for other international bodies, or core countries, to act in its stead. More use can be made of devices such as coalitions of the willing inside NATO, and the (little known) absence of a legal requirement of consensus in NATO decision-making.

Cohesion is not consensus; it needs to be understood in the future more in terms of getting the job done for the common good and less in terms of waiting for agreement by every member. Cohesion is deepened when decisions can be taken on a timely basis and implemented by those willing to do so, as long as the minority pledges not to undermine the majority. Such coalition actions do not bypass the alliance but enhance it. Bypass operations are also sometimes necessary, but should not be overused. The core cohesion among the advanced technological allies (the nato/G-8 plus group) has to be maintained, indeed upgraded; otherwise we could never keep up consistent economic and political pressures on would-be proliferators--and so keep down the cases of military enforcement to a workable remainder.

We also need to modernize our general thinking on proliferation in the light of these new realities. The NPT's leveling demand for universal disarmament was always unrealistic; it is now obsolete. The superpowers have drastically reduced their arsenals, and the danger from them is not in their numbers but in their security. As the former Russian parliamentarian and non-proliferation think-tanker Alexei Arbatov pointed out in June, only a supranational world government would make it possible to pursue general nuclear disarmament without destabilizing effects along the way. Today the NTT's disarmament demand could be replaced with an obligation for the nuclear powers to manage their arsenals better, take them off hair-trigger alert, coordinate them with joint planning, and even--though this is a very long-term goal indeed--aim at their ultimate integration. This is the only way back to the Baruch Plan, which aimed at unified control of nuclear resources and dangers.

For the moment, this ultimate vision seems almost as utopian as disarmament itself. But some aspects of it, as we have seen, are realistic and necessary now. It provides the right orientation for practical steps. General acceptance of Western global leadership is a condition for the success of non-proliferation. In any social order, norms can be efficiently enforced from above only if they are broadly supported and most of the time mutually enforced horizontally. Fortunately, the leadership role of the nato/oecd/G-8 countries is more widely accepted than it may seem at first sight. They have long been the leaders in global modernization and in providing the public goods of global security and efficient trade. Awareness of this reality has grown as the Western countries have ended their former centuries of internecine warfare. This awareness is in turn illustrated by the very fact that they have come to organize themselves as a core of global cohesion. Legitimacy has accrued accordingly. The old Cold War controversies have dissipated. The UN has come to accept NATO's regional and global roles. Other nations seek nowadays to be included in their joint structures, rather than trying to overturn them.

The period from the end of Soviet communism to 9/11 was a lost decade for non-proliferation. With the Gulf War, the process of reversing proliferation seemed to be getting underway, but little was done afterwards. Two administrations let opportunities slip through their fingers. Clients of the two sides of the Cold War proceeded to spin out of control and develop independent strategic identities. Islamism got a second wind. Terrorists gained global reach and WMD ambitions. The dangers metastasized.

September 11 finally changed that--with preventive war, in cooperation with Russia (among other states), against the Taliban, coercive diplomacy over Iraq, and then war. Despite embarrassments over Iraq, the process has continued with semi-coercive diplomacy against proliferation elsewhere--diplomacy that has borne unprecedented if uncompleted fruit in Libya and Pakistan. But Iran and North Korea remain as serious unsolved problems and potential crises. If both countries are persuaded by some combination of diplomacy and the use of force to abandon their nuclear programs, then the rollback of nuclear proliferation will have begun. If not, the other countries in those neighborhoods will inevitably acquire nuclear weapons for self-defense. Europe may instinctively prefer diplomacy to force in countering proliferation; the United States may reason that force is needed to help diplomacy work. Whatever their differences, both Europe and the United States jointly have the best chance since 1965 to institute a serious regime of counter-proliferation. It may also be their last.

Ira Straus is U.S. Coordinator of the independent international Committee on Eastern Europe and Russia in NATO.