In April 1961, one of the seminal think-pieces on proliferation appeared. This was Albert Wohlstetter's famous Foreign Affairs article analyzing the so-called "N + 1" problem. This formulation was Wohlstetter's way of characterizing the next incremental addition to the existing number of nuclear weapons states. In an elegant analysis focused mainly on the nuclear problem in Europe, he argued that the U.S. nuclear umbrella was the answer to the security needs of NATO's potential next nuclear states. He argued further that disarmament would only fuel Soviet ambitions, but that export controls and modest arms control measures had a role to play in limiting nuclear diffusion.

In this, as in so many other areas, Wohlstetter's ideas helped to shape his generation's thinking about the proliferation problem. But wholly new factors have arisen over the past four decades, and we need to think differently about the issue because the problem itself has changed. We can best see how it has changed by taking separately the two parts of Wohlstetter's simple "N + 1" expression.

First is the "N" factor: the number of existing nuclear-armed states. Today, the policy debate remains focused on the challenge of preventing those two or three states most desirous of joining that number from achieving their ambition. Now, as then, nuclear proliferation presents risks of major importance for international stability and U.S. security. The emergence of a nuclear-armed Iraq, Iran, or North Korea would be deeply unsettling, both regionally and globally. So too would be the leakage of nuclear weapons materials, technology, or expertise to both state and non-state actors. Stopping such proliferation remains a top policy priority, as it was in 1961.

But the nuclear dynamic is more complicated than suggested by "N + 1." There is also an "N - 1" phenomenon. The number of states opting out of the nuclear weapons business (South Africa, Ukraine, Belarus, Kazakhstan, Argentina, and Brazil) is roughly double the number working to get in. Moreover, the emergence since 1961 of de facto nuclear weapons states outside the superpower strategic framework (Israel, India, and Pakistan) has not so far changed the world in any fundamental sense, largely because their purposes are understood to be essentially defensive.

The proliferation phenomenon has been further complicated by the increased prominence of elements of the problem other than the nuclear one. Chemical weapons proliferated rapidly in the 1980s, in a process driven largely by their use in the Iran-Iraq war. A spate of biological weapons proliferation followed. But here too the trends are not straightforward. Implementation of the new Chemical Weapons Convention of 1997 is leading to a decrease in the number of states armed with such weapons (India and South Korea, for example, have signed the treaty and have promised to destroy their chemical weapons). In the biological area, there seems to be no increase in the number of states possessing or seeking such weapons since the number peaked at about a dozen in the early 1990s. If Iraq's biological warfare program is any indication, the proliferation of the 1990s may not be so much horizontal as vertical-in other words, the problem is now one of an increasing number and quality of such weapons among already existing possessors, rather than an increase in the number of possessors.

Then there is the rest of the proliferation problem: ballistic missiles, cruise missiles, advanced conventional weaponry, small and light arms, new supplier nations, new risks of non-state actors gaining access to nuclear/biological/chemical weapons (NBC) or technologies. And there is even a new category of concerns over the proliferation of the science and technology base, and the dual-use technologies that go along with it.

To understand these increasingly complex phenomena, analysts continue to reach into the conceptual tool kit assembled by Wohlstetter and others in an earlier generation. But what drove nuclear proliferation in the 1950s and 1960s-major power competition-does not drive the proliferation trends of the 1990s, which result more from the asymmetric strategies of regional powers. Nor does the debate about the consequences of proliferation as framed by Wohlstetter, Kenneth Waltz, and their colleagues capture the full range of present experience. If, for example, as Waltz argued, nuclear proliferation might be stabilizing if it strengthens deterrence among hostile powers, what are we to make of the secret Iraqi biological arsenal that was evidently intended to be used not as a deterrent but as a means of retribution?

If the problem has changed, so too must policy. This brings us to the second part of Wohlstetter's short formula: the "+ 1" part. With a singular focus on the small number of developed states then considering the desirability of independent national "nuclear strike forces", Wohlstetter prescribed a strategy "to abate, delay or control nuclear diffusion", one encompassing an American nuclear guarantee to Europe and integrated alliance nuclear planning, with a bit of arms and export control on the side.

Today, policy must continue to be effective in dealing with the states with nuclear ambitions. These are now typically American adversaries, not allies, a fact that dislodges the centrality of a U.S. nuclear guarantee in non-proliferation strategy. But policy must also be effective in dealing with the increasingly multifaceted nature of the proliferation problem. Toward this end, many more tools of policy have been created. Supplier restraints in the nuclear domain have been supplemented by similar restraints in the chemical, biological, missile, and conventional weapons domains. Non-proliferation has been supplemented by counter-proliferation. The non-proliferation benefits of arms control are also now more widely appreciated. Despite this profusion of policy instruments, however, their focus remains the "+ 1" problem, which is to say preventing states with weapons ambitions from achieving their aims.

But the diffusion of materials, technologies, and expertise that have both normal commercial and military uses-especially in the areas of mass casualty weapons-has made the policy agenda far more complex. Thanks to this "dual-use" phenomenon, most states now have the ability to make chemical and biological weapons (CBW), and to do so relatively quickly. Many more states than actually possess nuclear weapons have the ability to make them. A key question is what these states with latent weapons capabilities will choose to do with those abilities. Might they hedge against an uncertain future by cultivating those capabilities, perhaps to the point of acquiring virtual arsenals? Might they turn potential into actual possession? If one or two states in a particular region were to do so, would it touch off a domino effect within and beyond that region? How can the risks of a wildfire-like weaponization among states with latent technical capabilities be minimized, as they respond simultaneously to a worsening security environment by stepping up the readiness ladder?

Answers to these questions must begin with the recognition that not all potential proliferators have the same motives, or find themselves in comparable circumstances. There are three reasonably distinct types of states whose behavior will matter to the long-term success of non-proliferation: the determined, the dabblers, and the disinterested.

Those states determined to possess nuclear, biological, and/or chemical weapons are generally desperate to gain the strategic and operational leverage presumed to derive from them. This is the category most in the public mind today, and not surprisingly so. Examples include the de facto nuclear weapons states plus Iraq and North Korea.

The dabblers are those states exploring their weapons potential but that lack an immediately compelling strategic need. They cultivate a scientific base and would move to weapons production and stockpiling under certain circumstances. Examples here are hotly debated, but certainly include Iran and Taiwan. The states that plunged into CBW work following Iraq's examples in the 1980s and 1990s may also be dabblers.

The disinterested states are those with neither the programs nor the ambitions to exploit their latent capabilities for weapons purposes. Sometimes those capabilities are substantial. In the nuclear domain, Germany and Japan are prime examples. In the chemical and biological domains, any developed country has a substantial latent ability. Why do so many refrain from exploiting their weapons potential? External guarantees play a role for some. So too does history and politics. Some simply calculate that developing such capabilities would cause more security problems than it would solve.

Let us now look at these three categories more closely, in reverse order.

The disinterested category-happily constituting the vast majority of countries of the world-rarely gets the attention of the non-proliferation community, but these states deserve to be a part of the policy picture for several reasons. First, their latent capability might eventually be translated into weapons prowess-which could have far-reaching consequences, especially if the country in question were a major power such as Germany or Japan. Second, some of these states are what Sandy Spector has called repentant proliferants-that is, states that over the last few decades have formally forsworn nuclear weapons programs after taking initial-and sometimes substantial-steps in that direction. Usually the reversal has followed lengthy debate over what best serves their national interest. (South Africa and Ukraine, after all, make a much more credible case for the virtues of nuclear non-possession than does the rhetoric of those that determinedly continue to be nuclear weapons states.) Third, some are states that have prospered even in a generally insecure international environment without resort to any major armaments programs. Costa Rica is perhaps the best example here, and a model for others-after all, it has no military forces and did not create them even when its neighbors Nicaragua and Panama were in deep crisis.

There are yet other reasons to fit these states into the non-proliferation equation. Many of them are the recipients, conduits, and even generators of militarily sensitive technologies. Because they are so numerous, their participation in the international effort to prevent those technologies from reaching states with weapons ambitions is essential. Relatedly, the weapons-disinterested states must be active in the promulgation of the international norms about weapons and war and in the implementation of the multilateral treaty regimes embodying these norms. Without their participation, the international consensus against proliferation would be limited to a few countries mostly in the developed world.

The dabblers are states reported or reputed to have weapons development programs, but not compelling reasons for actually acquiring the weapons. These states are not motivated by immediate fears for their national survival. Some may have substantial weapons programs that have gained momentum largely on the basis of domestic political and bureaucratic factors. Some of these programs seem to have paused at certain thresholds related to weaponization, serial production, or declaratory policy, and today face an uncertain future as national leaders debate the evolution of national military capabilities-a process obviously contingent on political perceptions and external factors. Because states do not publicize these programs, it is difficult to gauge how numerous they may be. But they deserve to be in the non-proliferation equation because changes in security conditions can give rise to rapid movement toward unconventional weapons capabilities on their part. The speed with which such developments could occur is itself a source of worry, for there is nothing like an acute perception of time pressure to evoke a series of bad judgments.

Yet the policy debate focuses almost entirely on the third category-the determined proliferators. These are states whose leaders appear absolutely determined to achieve an unconventional weapons capability, or to continue improving one already attained, and who do so despite high costs and risks, due to some perceived overwhelming national interest.

In the U.S. policy debate, each tool of policy is scrutinized for what it contributes to preventing the success of the determined proliferator. Very often, the relevance and contributions of each tool to the other two categories of states is ignored. Arms control approaches are not likely to be especially effective for dealing with the determined proliferator, but they are valuable for enlisting the weapons-disinterested states as political partners in the non-proliferation effort, and indispensable for creating incentives for the contingent proliferator to abandon programs lacking an overriding strategic purpose. Export control approaches have a similar role in imposing costs on the dabblers and promoting cooperation among like-minded states, even if they are not always reliable in keeping sensitive technologies out of the hands of proliferators. Counter-proliferation, which is to say the strengthening of the U.S. ability to fight and prevail in regional wars in which aggressors threaten or use NBC weapons, is essential for creating yet more disincentives for the dabblers and the determined proliferators. It is also essential for reassuring those whose disinterest in acquiring NBC counters of their own depends to some extent on credible U.S. guarantees.

However much we may long for the tidiness embodied in Wohlstetter's "N + 1" concept, it is beyond our power to recreate the world of 1961. Enlisting the disinterested states and creating incentives for the dabblers to abandon their programs, or at least to remain under the threshold of weaponization, are as important to the long-term success of non-proliferation as is preventing North Korea, Iraq, and Iran from achieving their nuclear ambitions.

Yet the government as a whole still lacks an agenda that effectively encompasses the many facets of the proliferation problem. To be sure, it has an agenda-and as argued above, an increasingly broad one. Lots of bureaus, agencies, and departments are working the proliferation problem with myriad programs and policies. But there are signs that all this effort is not particularly well orchestrated. For example, absorption of the Arms Control and Disarmament Agency into the Department of State has reinforced the tendency to narrow the non-proliferation emphasis to the "rogue states", and to submerge arms control and non-proliferation issues in relations with the dabblers and disinterested states into the larger bilateral dialogue. As another example, the disputes about weapons programs in Iraq and North Korea graphically illustrate the fact that government is better at creating anti-proliferation instruments than at enforcing them. On the more positive side, after an early bureaucratic feud that left the impression that the effort to prevent proliferation was going to be abandoned in favor of an effort to cope with its consequences militarily, there is now widespread agreement that counter-proliferation and non-proliferation are complementary.

A more integrated and effective strategy cannot be won simply by creating new organizational structures or appointing a new proliferation czar. The chief deficiency of policy is not bureaucratic but political. Everyone working the problem in government understands that preventing proliferation is important but there is no generally accepted sense of why and how all the pieces of policy are supposed to fit together. The principles and purposes of U.S. policy remain set out in largely Wohlstetter-like terms. This reinforces the tendency to equate proliferation policy with nuclear non-proliferation. It also reinforces the tendency to treat non-proliferation as a discrete and separable policy problem, when in fact it cuts across large segments of American foreign and defense policy and can be dealt with effectively only as an integral component. Policy could be made more effective if someone in the bully pulpit would restate the principles and purposes of policy, define the components of American strategy, and identify the synergies among policy instruments. Without such a strategic perspective, there is no way to decide where proliferation fits in U.S. priorities in any given instance, how to handle conflicting policy interests as they arise, or how to determine sensible budgetary allocations among the various agencies.

The absence of a strategic perspective also brings with it a political cost. Without a sense of why and how the elements of policy fit together, individual pieces are vulnerable to poaching. Each piece has its strong critics (often with views firmly rooted in Cold War-vintage strategic perspectives). Some see arms control as a sellout of the national interest; others see counter-proliferation as an abandonment of the pure principle of non-proliferation. Some argue that the proliferation problem has been exaggerated, and that American power is sufficient in its "unipolar moment" to pay less rather than more attention to proliferation; others, contrarily, think things are so bad that we should jettison non-proliferation efforts altogether and instead prepare urgently for a world in which such weapons are widely proliferated and actually used.

But U.S. interests are best served by husbanding all of the tools of policy that have been developed over the years because, again, particular tools are relevant to different parts of the problem. The synergies among these tools, too, may be as important as the contributions they can make singly. Arms control is necessary if export controls are to be effectively coordinated among the growing number of supplier states. Arms control regimes can also help legitimize certain types of enforcement actions against proliferators, including coercive actions. Counter-proliferation capabilities are needed to deter, defeat, and punish the users of weapons of mass destruction and thus to deny them the coercive value of threats deriving from those weapons.

It is legitimate to ask whether the United States is capable of pursuing so comprehensive an agenda in an era of increasing partisanship over foreign policy. The attack on administration policy has been continuous. Not obliged to offer a strategic perspective of their own, administration critics can subject every instrument of policy to the hardest test (the determined proliferator test), and shine a bright light on its shortcomings. They have made a lot of headway. On balance, this sort of bureaucratic potshotting works against the national interest by weakening the political foundations necessary for implementing negotiated instruments, enforcing existing obligations, and building the right kinds of military forces at the same time. American leadership of the non-proliferation effort is no longer taken for granted by our historic partners in this process-and certainly not by some of our most dangerous potential opponents.

Re-reading Albert Wohlstetter's 1961 article reminds one of how much the world has changed over four decades. It is a reminder that potential proliferators are not few but many, as most states have been empowered by economic and technical developments to build quickly high-leverage weaponry with impressive strategic reach. It is also a reminder of the diminishing capacity of the United States to achieve non-proliferation results internationally by extending a security guarantee or two, or by orchestrating a few trade restraints.

Perhaps there is virtue in the necessity of engaging ever broader international coalitions in the fight against proliferation, for the best way to prevent states from hedging against uncertain futures is to enlist them in creating stable ones. Recognizing that necessity points to new leadership requirements for a United States whose place and role have changed, but whose leadership remains essential to the larger international effort. On the necessity of American leadership in this portentous policy area, a re-reading of Wohlstetter's article also reminds us of what has not changed over the years, and is not likely to either.

Essay Types: Essay