A global ethic for the twenty-first century will be different from that of the twentieth century. While themes of normative and political continuity will exist, humankind's main moral challenges have changed. Between the two centuries lie the end of the cold war, the terrorist attacks of September 11, 2001, the global financial crisis, and the double transformation of the structure of power in world politics and the norms of sovereignty and intervention. Nuclear weapons will remain high on the agenda of a global ethic, but they will not hold as dominant a place as they did in the past century. This essay, focused on the continuing moral challenge of nuclear weapons, recalls the intellectual and moral lessons of the last century and identifies three leading issues in nuclear ethics today: post–cold war challenges to nonproliferation and deterrence, the new challenges posed by the terrorist threat, and recent proposals for Going to Zero.
Remembering and Reviewing the Past: 1945–2000
The French philosopher Raymond Aron entitled one of his essays “From Sarajevo to Hiroshima”Footnote 1; similarly, a snapshot of the past challenges of nuclear weapons could be entitled “From Hiroshima to Prague.” Such a snapshot would encompass events from the only use of nuclear weapons, through the tradition of nonuse, to President Obama's endorsement of the idea of going to zero nuclear weapons.
In the opening pages of Just and Unjust Wars, Michael Walzer notes the similarity of the language of ethics and the language of military strategy.Footnote 2 An example of this parallel is evident in the simultaneous and similar challenge that the advent of the nuclear age posed for strategists and moralists. Bernard Brodie, a preeminent military historian and the editor of the first major analysis of the nuclear age (The Absolute Weapon, 1946) spoke for the strategists on August 7, 1945—the day President Truman announced the bombing of Hiroshima—when he remarked to his wife, “Everything I have written is obsolete.”Footnote 3 No single person spoke for ethics and morality with the same alacrity in 1945, but the ethical challenge posed by Hiroshima and Nagasaki was clear for all to see. The dominant moral tradition of the ethics of war had held that the only morally legitimate use of force was a limited one—limited in its purposes, its methods, and its intention. In the space of a week, climaxing a war that claimed over 50 million lives, two uses of atomic weapons had lodged a frontal challenge to the idea of the limited use of force. To some degree the twentieth century should have prepared both strategists and moralists for the challenges they now faced. Two world wars claiming roughly 10 million and 50 million lives had been fought with very little explicit moral restraint. Indeed, a dominant tactic of 1939–1945 had been obliteration bombing carried out on both sides with minimal moral objection—a grim portent of what lay ahead. John Ford's essay “Obliteration Bombing” (1944) stands out as an unyielding witness to ultimate limits transgressed often and without major objection.Footnote 4 His witness, while honored in memory, had minimal effect at the time.
The political-strategic debate about what to do with nuclear weapons unfolded over the next decade in a series of disparate proposals, which ranged from plans for total disarmament to simply recognizing the advantages of the new weapon and planning to use it, if necessary.Footnote 5 Into this political argument came calls for the integration of nuclear weapons into a coherent strategy. Henry Kissinger was an early proponent of the need for “integration,” arguing for such a strategy in Nuclear Weapons and Foreign Policy.Footnote 6 This integration, on the political-strategic front, began to take shape by the early 1960s. Between those who sought “to normalize” nuclear weapons (in other words, treat them like other weapons) and those who sought their elimination through disarmament, a new consensus, distinct and different, appeared. On the one hand, it moved the argument from the use of nuclear weapons to deterrence; on the other hand, it moved the focus from disarmament to arms control, a more limited objective. Both concepts have been contested throughout the nuclear age, but they held the day throughout the cold war.
The moral arguments regarding nuclear weapons matured more slowly. The Federal Council of Churches in the United States made some early statements on the subject; the International Institute for Strategic Studies in London was founded to address the political and military issues of a new age; characteristically, Reinhold Niebuhr joined the debate incisively, early, and often. But it took the entire decade of the 1950s to sort out the moral analysis of the nuclear challenge. The results, not surprisingly, yielded pluralism. These new challenges recast the classical distinction within the Christian churches between pacifists and just war defenders. Some in the latter group, who had espoused the idea of just war during both world wars, found Hiroshima and the threats of the nuclear age to be a dividing line. They developed a position of “nuclear pacifism” based on some mix of jus in bello principles (of discrimination and proportionality) to rule out both nuclear use and deterrence. Others, unwilling to cast aside an ancient moral tradition as unusable, were left with three basic questions to answer. First, could any use of nuclear weapons be morally legitimate? Second, how should we judge the morality of nuclear deterrence? And third, was there any possibility of moving beyond a nuclear armed world?Footnote 7
From these foundations, strategic and moral, the nuclear debate proceeded. Often described as “arcane” (and sometimes described as “theological”), the policy arguments produced multiple distinctions: crisis stability vs. arms race stability; first use vs. first strike; counterforce vs. countervalue targeting; firebreaks vs. escalation. The strategic debate proceeded in geometric progression, growing ever more intricate, open to intense disagreements, and subject to political purposes on all sides.
The moral debate had its own pace and participants. To some degree it can be argued that the nuclear age led to a revival of just war scholarship. The extent of the new challenges was made even more prominent by the memory of how marginal the moral tradition had been in the twentieth century. The theologians, philosophers, and religious institutions that addressed the nuclear questions often made reference to past failures. They treated the historical tradition of moral discourse about war as a resource, but they were acutely aware that this discourse faced a challenge beyond anything the major voices of the past had encountered.
The moralists entered the strategic debate with varying levels of expertise, and they often reflected some of the divisions found among the strategic thinkers. Those who brought a clear-cut consequentialist perspective to the argument often simply affirmed the policy of nuclear deterrence; in other words, that the threat was great and deterrence was the only answer. Others found it to be a more complicated question. The nuclear pacifists focused on the moral category of intentionality: credible deterrence, even if it “worked,” involved an intention to do evil. The argument was made at the level of policy and personal conscience for those designated to carry out a nuclear response. Perhaps the dominant voice of the age was that of Paul Ramsey, who sought—at great length and with excruciating care—to fit both use and deterrence into a policy marked by a narrow range of targets determined by jus in bello criteria.Footnote 8 Ramsey was neither a consequentialist nor a nuclear pacifist; his problem was trying to find a strategy that met his criteria. Michael Walzer also staked out a singular position. Unconvinced that nuclear use could be justified morally, but impressed by the unique role of deterrence, he concluded:
Supreme emergency has become a permanent condition. Deterrence is a way of coping with that condition, and though it is a bad way, there may well be no other that is practical in a world of sovereign and suspicious states. We threaten evil in order not to do it, and the doing of it would be so terrible that the threat seems in comparison to be morally defensible.Footnote 9
While theologians (such as Niebuhr, Ramsey, and John Courtney Murray) led the moral debate in the 1950s, they were joined by historians (such as James T. Johnson), as well as philosophers of various schools, and then, in the 1970s and 1980s, by political scientists and strategists (such as Bruce Russett, Joseph Nye, Hedley Bull, and Stanley Hoffmann). All of these moral positions involved a detailed version of an “ethic of means,” which focused less on the political context of the cold war and much more on the unique threat of both nuclear weapons and the strategy that directed them. This focus, which continued the discussion of jus in bello, was periodically criticized for downplaying the threat posed to the West by the Soviet Union, a critique well represented by the work of William O'Brien of Georgetown and Michael Novak of the American Enterprise Institute, among others.Footnote 10 Those stressing the threat posed by the superpower conflict believed that greater emphasis on jus ad bellum issues of just cause and the nature of the Soviet threat should frame any analysis of the means used to oppose it.
One position—that which was taken by the National Conference of Catholic Bishops (most notably in the 1983 pastoral letter The Challenge of Peace)—was regularly subjected to this critique. The Pastoral Letter acknowledged the role that nuclear deterrence had played in the superpower relationship, but it also challenged the moral foundations of deterrence. The challenge of the letter did not produce a condemnation of deterrence, but allowed for what the bishops called “strictly conditioned moral acceptance” (paragraph 186). The basic condition was that deterrence should serve as a transition to progressive disarmament. Other conditions included an absolute prohibition against direct attacks on civilians, and support for a “no first use” policy. The critics were correct to classify the letter as primarily focused on an ethic of means. The Challenge of Peace did not ignore or dismiss the threat posed by the Soviet Union, but it certainly focused its attention on the jus in bello arguments. The response by the bishops to their critics was twofold. First, the threat posed by the cold war was so clear that the jus ad bellum dimensions were virtually self-evident. Second, the key question was, therefore, what kind of response to the evident threat would pass the twin tests of strategic effectiveness and moral legitimacy. This question drove the bishops to reckon principally with jus in bello matters. They set out a position that could be functionally located between those of Ramsey and Walzer without identifying totally with either. Like Ramsey, they sought to adapt the limits of the traditional just war ethic to nuclear use and deterrence. In doing so, they did not reflect Ramsey's confidence that use could be controlled. With Walzer, they doubted the morality of nuclear use of any kind, but they wanted to preserve a role for deterrence.
In adopting their position of “conditional acceptance,” the bishops drew on a pivotal statement by Pope John Paul II addressed to the United Nations in 1982:
In current conditions “deterrence” based on balance—certainly not as an end in itself, but as a step on the way to progressive disarmament—may still be judged to be morally acceptable. Nonetheless, in order to ensure peace, it is indispensable not to be satisfied with this minimum, which is always susceptible to the real danger of explosion.Footnote 11
Conditional acceptance of deterrence acknowledged the historical fact that deterrence had preserved peace of a sort for over thirty years. The conditions set forth in the bishops' letter were drawn for the most part from the arms control policies of the time. The strategy of conditional acceptance primarily sought to provide space for political measures aimed at changing the basic relationship between the superpowers, seeking over time to change the relationship in such a way that deterrence would no longer reflect a balance of terror. In the end, The Challenge of Peace reflected positions already developed in the nuclear age, but it set out a specific version of them along the spectrum of moral argument. It also reflected a specific moment in time; while its principles are still useful, the challenges have changed substantially in this new century.
Defining Changed Challenges
The end of the cold war opened a new chapter in the history of the nuclear age. The global competition between the United States and Russia has been substantially diminished, but thousands of nuclear weapons survive today. The post–cold war period has produced its own challenges and opportunities. Without seeking to be exhaustive, this essay examines three issues: first, the new role of proliferation in world politics; second, the new threat of nonstate actors committed to terrorism; and third, the recent call to pursue a world without nuclear weapons. Each of these issues embodies ethical and strategic themes about which there is only modest consensus and persistent division.
Nonproliferation after the Cold War
The threat of nuclear proliferation has troubled diplomats and statesmen since the 1960s. The most quoted statement of the problem has been John F. Kennedy's expressed fear in 1963 that a U.S. president could face a world of twenty to twenty-five nuclear armed states by the 1970s. That fear has not materialized, but the end of the cold war and the events of 9/11 have combined to escalate the proliferation threat to the very center of the nuclear agenda. Until the end of the cold war, proliferation was treated seriously, but always secondarily, to superpower relations. Paradoxically, the decline of superpower competition has opened space for some states to consider nuclear acquisition. The rise of nonstate terrorism has intensified this problem, opening an entirely new challenge that had received scarce attention before 2001.
The diplomatic centerpiece of a strategy to address horizontal proliferation among states has been the Non-Proliferation Treaty (NPT), signed in 1968, which has been regarded as a cornerstone of nuclear diplomacy over the last four decades. In many ways it was a surprising accomplishment.Footnote 12 The 1960s was a time of intense superpower competition in all aspects of their relationship. Nonetheless, the two superpowers found common ground in the negotiations leading to the NPT. Although they were not prepared to make deep cuts in the area of vertical proliferation, the United States and the USSR both saw the danger of nuclear competition among multiple states, some of which were in highly conflicted local or regional settings. The product of the NPT negotiations was a compact, concise treaty that contained a contract, a promise, and a pledge. The contract was embodied in Articles I and II: in Article I, nuclear state signatories committed themselves not “to transfer to any recipient whatsoever nuclear weapons or other nuclear explosive devices,”Footnote 13 while in Article II nonnuclear signatories made the complementary commitment not to seek or receive such weapons and not to manufacture them. The promise in the NPT was contained in Articles III and IV: it essentially stated that nonnuclear weapon states would not be deprived of nuclear energy for peaceful purposes. The pledge was contained in Article VI, where the nuclear signatories committed to pursue negotiations to halt the nuclear arms race and pursue nuclear disarmament.
Three comments can be made about the NPT forty-five years after it was signed. First, the treaty and the nonproliferation regime it created have several accomplishments to their credit. The most evident result has been what Tom Schelling has called “An Astonishing Sixty Years”—that is, sixty years during which no nuclear weapon has been used.Footnote 14 A more directly attributable result is the fact that the NPT has 188 signatories. In addition, since the signing of the NPT, several states, including Argentina, Brazil, and Sweden, have turned back from pursuing nuclear weapons. Beyond these, four states—South Africa, Belarus, Kazakhstan, and Ukraine—have given up nuclear weapons. All of these positive events had domestic and international influences, but the NPT had a demonstrable role in each of them.
Second, these accomplishments lie in the past. The present condition of the NPT is often described in more somber tones. In 2010, Graham Allison and Charles Ferguson wrote in Foreign Affairs about the rising cynicism regarding the NPT regime.Footnote 15 An abiding challenge to nonproliferation is the fact that the NPT aims to manage nuclear weapons on a global basis, but the reason states are tempted to go nuclear depends primarily on local or regional dangers or opportunities. Iran, for example, may have multiple reasons for wanting nuclear weapons, one of which may be a desire to exercise hegemonic influence in the Middle East.
Third, other threats to the NPT arise from changes in the international environment. Two principal threats that differ substantially from the time when the treaty was signed are the democratization of nuclear knowledge and the globalization of markets for fissionable material. It is still not simple to make a nuclear weapon, but the basic understanding of the challenge is no longer confined to nuclear states or states with advanced scientific establishments. As Allison and Ferguson have commented on the problem of fissile material:
The hardest part of making nuclear weapons is producing fissile material: enriched uranium or plutonium. . . . A nuclear regime that allows any state with a nuclear energy plant to build and operate its own enrichment facility invites proliferation.Footnote 16
Nuclear knowledge and fissile material are more easily shared in an interdependent world with a global economy, and these positive features of international political economy make the successful continuation of the NPT regime more difficult. Allison recommends an international fuel bank governed by the International Atomic Energy Agency, but also acknowledges the difficulty of creating such an institution.
The political-strategic literature on proliferation typically emphasizes these local, regional, and systemic issues, all of which make nonproliferation more challenging today. But embedded in the proliferation challenge is another critical topic: the ethical character of the NPT regime. The ethical character of the regime is seldom focused upon,Footnote 17 perhaps because it may appear self-evident: the NPT seeks to contain nuclear weapons and reduce nuclear danger, so no further defense is needed. The problem here for a global ethic is that not all actors see the issue so clearly and simply. When the argument about the eroding hold the NPT has on many states is raised, the ethical character of the regime surfaces more specifically. To the question of what it will take to maintain the effectiveness of the NPT, the answer is multidimensional. Diplomacy and deterrence will surely be necessary, but not sufficient; coercion alone cannot contain the proliferation threat over time. The regime must also be regarded as legitimate and fair. These are normative terms; they rely on the participants in a regime to acknowledge that the regime fulfills an essential purpose, is in the interests of all participants, and distributes burdens and benefits in an equitable fashion.
Does the NPT meet these standards? What is the moral character of the treaty regime? It must be said that the NPT is an inherently discriminatory treaty. It is, after all, purposefully discriminatory. This gives it a unique or at least rare character among modern diplomatic agreements. Many such agreements—for example, in the area of trade—are unequal, but they usually promise to overcome inequity. Not so with the NPT; it seeks radical inequity as its first purpose. In that sense it contradicts a presumptive principle of social relationships and distributive justice. Equality of individuals is a foundational idea of the concept of a global ethic, as Michael Ignatieff has argued in the pages of this journal.Footnote 18 To be sure, one cannot simply take ideas about the relationship between individuals and apply them to the world of states. But some analogous conception of equality among states is necessary.Footnote 19
One counterargument to the equality critique of the NPT is that such concerns should not apply to a treaty limiting nuclear weapons. The point is that they are not benefits to be desired. There is a certain prima facie persuasiveness about this response, but it has met with strong resistance among key states. To several such states located in conflicted areas or regions of the globe, nuclear weapons appear to be a benefit.Footnote 20 Indeed, as Paul Bracken states in his recently published The Second Nuclear Age, “atomic weapons have returned for a second act.”Footnote 21
The NPT by itself is not an effective answer to these deeply held conceptions of national interest. But without the NPT the number of states in search of greater security through nuclear weapons could easily multiply. How, then, should a reasonable defense of the NPT be constructed? The treaty is just one (if central) component of a broader array of instruments and ideas devoted to “managing” the nuclear age. Deterrence and arms control, hotlines and redlines, firebreaks and permissive action links have all been part of a regime dedicated to preventing the use and spread of nuclear weapons without sacrificing the essential interest of states. The regime has been based on a broad consensus that a nuclear exchange of the kind threatened during the cold war would have catastrophic consequences for the world as a whole. Few would dispute the judgment that crossing the nuclear line today, even in a limited fashion, would be a profoundly destabilizing event. Even in the face of this conviction, however, the inequality argument needs to be answered as one part of a defense of the NPT.
Stating the inequality argument in its most assertive form takes the case to the heart of modern international relations. The argument is familiar but still functional in many dimensions of world politics. It begins with the anarchic character of international relations—the idea that no single institution has the capacity to guarantee the security of states in world politics. Even recognizing the interdependent and globalized character of world politics today, and even within the legal structure of the UN Charter, the sovereign state remains the basic unit of international responsibility and authority. Sovereignty asserts a formal equality of states in spite of great material differences of size, wealth, and power. Sovereignty also implies the right of each state to provide for its own security. Nuclear weapons are possessed by some states, and their possession constitutes a major dividing line in world politics. The pursuit of nuclear weapons is totally beyond the capacity of the vast majority of states. But for some, their desire for nuclear status is supported by the equality argument. This stark statement has been qualified, however, by the NPT: signatories have willingly committed not to pursue an objective that, in a purely theoretical sense, they could claim a right to achieve. Even among signatories of the NPT the inequality argument remains potent. While signatory states have freely consented to an “inherently discriminatory” regime, simply recognizing the consent of these states is not a sufficient argument for the legitimacy of that regime. Leaving the argument at that level echoes Thucydides' dictum that the strong do what they will and the weak do what they must.
The moral as well as the political-strategic case for the NPT is best made in consequentialist terms. Consequences are a limited dimension of the moral order, but in political relationships assessing consequences of policies is an essential, if not total, method of moral analysis. Having acknowledged the formal equality of states, the consequences of facilitating or enhancing the emergence of what Bracken calls a “multipolar nuclear world” must be assessed. The consequence of increasing the number of nuclear states does not make the use of nuclear weapons inevitable, but it does increase the possibility of either intentional or unintentional use. It is true that any use of nuclear weapons today would not involve the kind of exchange contemplated during the cold war, but any use will violate the hard-won barrier of what Schelling calls “the nuclear taboo.”
In calculating the consequences of nuclear proliferation and/or use, what weighs against equality claims of individual states is the issue of systemic safety—the safety of the international system as such. Systemic safety is a category appropriate for the content of a global ethic. It involves the balancing of individual claims (by states) against the possibility of managing the nuclear age in such a fashion that it is preserved from nuclear chaos. To be sure, the primary responsibility for systemic safety falls on the existing nuclear states. The Canberra Commission stated what needs to be said:
Nuclear weapons are held by a handful of states which insist that these weapons provide unique security benefits, and yet reserve uniquely to themselves the right to own them. The situation is highly discriminatory and thus unstable; it cannot be sustained. The possession of nuclear weapons by any state is a constant stimulus to other states to acquire them.Footnote 22
Responding to this argument is essential in any defense of the NPT, but to defend the NPT regime does not imply that the current conditions should be extended indefinitely. In the interim, however, the case for the NPT needs to be made not only as a critique of nuclear states but also as an argument for the moral legitimacy of a flawed regime. Systemic safety has many component elements, but one of them is to make the use of nuclear weapons as unlikely as possible. Insofar as the NPT contributes to that goal, a consequentialist case can be made for it.
That normative judgment, however, must be complemented by a political-strategic agenda that seeks to reduce the discriminatory effects of a world divided by nuclear possession. The NPT can be defended morally, but only if there are continuing efforts to reduce inequalities (beyond those related to the possession of weapons) as far as possible. The treaty itself acknowledges this requirement in Article VI, which commits nuclear states to both arms control and disarmament. This article has generated much debate about whether the possession of nuclear weapons by some is the reason other states pursue them. The Canberra Commission basically argues this case. My sense is that there is enough validity to it to assert its value, but it also can be argued that this is not the primary reason for proliferation. Regional tensions and the aspirations of states to exercise greater political power seem to be stronger influences. Beyond Article VI, the objectives stated in Articles III and IV guaranteeing that nonnuclear states will not be deprived of nuclear energy for peaceful purposes are more significant than ever. In spite of warnings about the safety of nuclear energy, states pursue it in increasing numbers. A recent issue of Daedalus has devoted multiple essays to the theme of meeting energy needs without sacrificing the purposes of the NPT.Footnote 23
Significantly, the NPT articles do not address the status that nuclear weapons provide a state in the hierarchy of world politics. The most concrete example of that privileged status is that all five members of the UN Security Council are possessing states. In addition, nuclear states are generally considered to be in the category of “Great Powers,” with the implied influence that derives from this image. It is also no coincidence that over the last twenty years, when military intervention has been undertaken for humanitarian reasons (such as in Somalia and Kosovo) or for purely political reasons (such as in Iraq), no state possessing nuclear weapons has been the object of intervention for any reason.
The case for the NPT will have to be a combination of normative and political elements. It needs to meet tests of effectiveness and fairness. Given the world that has taken shape since 1945, states and people (both the subjects of a global ethic) cannot afford to be without the NPT, but living with it requires a recognition of its limits as well as its values. Some inequality in the service of safety is justifiable, but steps must be taken to keep inequities to the lowest level possible.
Nonstate Actors and Terrorism
The September 11, 2001, attacks by al-Qaeda on the United States significantly expanded the challenge of managing the nuclear age. In Nuclear Terrorism: The Ultimate Preventable Catastrophe, Graham Allison describes the new stakes of the problem: “Nuclear terrorism is not only an existential threat to the idea of America, it is also a threat to civilization as we know it. A nuclear terrorist attack is the face of nuclear danger today—the post–Cold War successor to the specter of global nuclear war that hung over previous generations.”Footnote 24 For most of the nuclear age—indeed until 2001—the focal point of concern about nuclear weapons had been the policies and capabilities of sovereign states. The enormous body of literature produced between 1945 and 1990 about managing nuclear relationships centered on states, especially the superpowers. Proliferation was considered primarily in terms of which states were candidates either for protection or proliferation. In this vein, Michael Mandelbaum distinguished among three groups of states: allies, orphans, and rogues.Footnote 25 After 9/11, states—especially Iran, North Korea, India, Pakistan, and Israel—were still key factors in the nuclear equation, but the analysis had to be significantly expanded.
Two features of the 9/11 attacks were directly pertinent to proliferation policy: they were carried out by a nonstate actor and they employed terrorist tactics. While international lawyers have long distinguished the status of participants in a domestic civil conflict, neither the moral tradition nor the political-legal tradition recognizes nonstate actors as legitimate agents of war. Politically and strategically, these forces constitute a new threat, but they do not do so under the cover of moral or legal legitimation. Nor did the attacks pass the standard of jus in bello; terrorists attack “soft targets,” that is, civilians. Hence, they directly violate the principle of discrimination. The consensus and judgment reflected in UN resolutions and the policy of states was that the 9/11 attacks violated both jus ad bellum and jus in bello. These judgments, however, do not dissolve the threat that transnational terrorism poses concerning nuclear proliferation. The threat is directly related to what might be called the logic of terrorism. This logic encompasses not only the preferred targeting doctrine of terrorists but also the willingness of terrorists to sacrifice themselves purposefully as part of their strategy. Suicide bombers exemplify this characteristic.
The logic of terrorism confronts an idea at the heart of the nuclear age: deterrence. During the cold war, deterrence was the defining strategy in the superpower relationship. Since the nature of that relationship offered little ground for compromise, the rivalry came to depend on a similar understanding of deterrence. The concept was neither attractive nor humane; it functioned by the threat of overwhelming mutual destruction. Central to the success of deterrence was a shared concept of rationality. The strategy was often described as “the rationality of irrationality.” Both sides possessed a common, if not identical, understanding of “unacceptable damage”—that is, the widespread destruction that would occur if deterrence failed. As indicated earlier in this essay, deterrence was the most debated moral issue during the cold war, both because of the targeting strategy it employed and implied, and because of the catastrophic damage it promised.
In the contemporary proliferation debate the issue of deterrence is much less dominant. How does deterrence succeed in a multipolar nuclear system? To be sure, this is not a new question: five states possessed nuclear weapons throughout the cold war, but the dominance of the two superpowers imposed a certain discipline on all their actions. With bipolarity now a memory, and with almost double the number of nuclear states today, deterrence now plays a more limited role. That role is most severely limited, however, by nonstate actors committed to terrorist tactics. In two different ways they erode—perhaps nullify—the role of deterrence. First, deterrence depends on the threat of retaliation, but this promise of retaliation needs a specific target, an “address”; deterrence without specification of a target-set is a vague threat to nuclear terrorists. To be sure, identifying the state from which terrorists operate provides a target, but as with the case of the Taliban and al-Qaeda, some determination of complicity and cooperation between states and terrorists is needed to justify any large-scale retaliation. Second, the psychology of terrorists may have its own logic, but it may not be one that judges widespread retaliatory destruction as too high a price to pay for carrying out a nuclear terrorist attack. There are multiple forms of rationality at work when calculating the logic of war and peace, and it is risky to assume that the logic of terrorism fits within the logic of deterrence.
Focusing on types of response to terrorism, while necessary, too quickly gives up on prevention. For states, and particularly for nonstate actors, the strategy needs to be multidimensional. Immediately after 9/11, former secretary of defense William Perry set out a strategy of prevention, deterrence, and defense.Footnote 26 Prevention is the highest priority; maintaining the nuclear taboo is the principal objective after more than six decades of success. Prevention is about intelligence, about international cooperation among law enforcement, about building political networks among states and others. Perry has a role for military response, but he also resurrects the idea of defensive systems with a more modest goal than they had during the cold war. Using prevention, deterrence, and defense in an effective strategy that postpones (but does not eliminate) the need to go from the threat of force to the use of force is a good example of invoking the just war criterion of last resort.
Going to Zero
This essay began by recalling the beginning of the nuclear age in world politics. In the years immediately following Hiroshima and Nagasaki, one idea that was debated in several quarters was that of general and complete disarmament (GCD). Both the United States and the Soviet Union formally espoused this goal, but differed substantially about the means for its achievement. As noted above, as the nuclear age proceeded, the focus shifted from disarmament to arms control—a more modest objective, but one that produced some concrete results. The GCD approach continued at the UN Conference on Disarmament in Geneva, but the primary locus of negotiations shifted to forums controlled by the superpowers.
The idea of a general and complete disarmament has resurfaced in the twenty-first century under new auspices and using new arguments. In 2007 and 2008, four veterans of U.S. defense and foreign policy—Henry Kissinger, Sam Nunn, William Perry, and George Shultz—authored essays in the Wall Street Journal calling for a renewed campaign to abolish nuclear weapons on a global basis.Footnote 27 Unlike other efforts seeking to revive the idea of a GCD, these articles have sparked significant interest and response inside the United States and abroad. Two reasons set this initiative apart from others. First, the cold war is no longer the context in which such ideas are evaluated. To be sure, new and different dangers exist today, but these help to catalyze current debate about Going to Zero (GTZ) rather than squelching it. Second, the nuclear debate has always been influenced by voices of authority. A relatively small community of people who have devoted their lives to service and scholarship—inside and outside the government—has carried unique weight when its members spoke on the topic of nuclear weapons. In this way the four authors of the two Wall Street Journal articles are voices of substantial authority. None of the four is now in government service, but their proposal about GTZ was given a significant boost when President Obama spoke in Prague in 2009:
So today I state clearly and with conviction America's commitment to seek the peace and security of a world without nuclear weapons. This goal will not be reached quickly—perhaps not in my lifetime. It will take patience and persistence. But now we, too, must ignore the voices who tell us that the world cannot change.Footnote 28
The positions and proposals of the four statesmen can be summarized as follows:
• The nuclear age has reached a “tipping point,” as there are now urgent threats of proliferation, but also opportunities for decisive action;
• Decisive action must begin by promoting widely a vision of a nuclear-free world, then developing a long-term realistic plan to implement that vision in steps;
• The division of the globe into nuclear and nonnuclear states is neither stable nor sustainable over time;
• Nuclear deterrence in the form developed during the cold war cannot simply be replicated to meet contemporary threats emerging in the world today, especially from terrorist groups in search of nuclear weapons;
• Nuclear technology and materials are currently too accessible to multiple actors;
• Russia and the United States, the two largest nuclear powers, must lead the way toward a nuclear-free world.
The coauthors also acknowledge the specific obstacles to their vision, and offer a series of proposals that they believe could be implemented immediately. To their credit, they continually stress the challenges that their proposals face, and they stress that their ideas are in need of dialogue and debate among states, within states, and among all those who have shaped the nuclear debate thus far.
Some of those invited to respond have offered strong critiques of the idea of GTZ. One argument is that this goal would be extremely difficult to achieve, but another criticism questions whether “nuclear zero” would in fact be preferable to the current state of affairs. Thomas Schelling, a master of strategic thought and recipient of the Nobel Prize for Economics for his work related to nuclear strategy, expresses such a view. Schelling treats the Shultz et al. proposal with respect and care, describing it as “a serious discussion of the possibility of utterly removing nuclear weapons from planet Earth.”Footnote 29 But he clearly has serious doubts about it, noting that the proposal does not explicitly address the question, “Why should we expect a world without nuclear weapons to be safer than one with (some) nuclear weapons?”Footnote 30
To play out his question, Schelling depicts a series of mobilization scenarios by several nuclear states, all of which are “starting from zero” but are seeking to rearm. He paints a sobering picture of states with “hair trigger mobilization plans to rebuild nuclear weapons” and with plans to target nuclear facilities in other states preemptively. For Schelling, a nuclear zero world would be a “nervous world.”Footnote 31 Schelling does support major cuts in nuclear forces, but he sees a substantial difference between a world of fewer nuclear weapons and one with none. And while he admits that the goal of a world without nuclear weapons is an attractive one, he warns that, in the pursuit of such a goal, states and strategists could create a dangerous and unstable situation wherein older ideas regarding deterrence are no longer operative.
Where does the recent discussion on Global Zero fit in the ethical frameworks derived from previous nuclear debates? First, much of the literature of the nuclear age describes Hiroshima as a turning point in history, then goes on to ask if there will ever be any escape from the threat of nuclear destruction. The Shultz et al. proposal is an attempt to design such an escape. But while the Shultz team sees a dangerous “tipping point” ahead, Schelling speaks of a state of “nuclear quiet.”Footnote 32 Empirical differences of perception on the state of the nuclear regime shape ideas about how urgently change is needed.
Second, in the normative literature (whether theological or philosophical), nuclear weapons were never given a positive evaluation. The most that was ever argued for was a posture of toleration. Today, the Going to Zero debate may increase skepticism about toleration among some participants.
Third, in spite of Paul Ramsey's heroic efforts to fit the use of nuclear weapons into the restraints of jus in bello, the idea of justified use always stood at the margin of the moral universe. The Challenge of Peace located nuclear weapons there—with less confidence than did Ramsey. What saved nuclear weapons from a clear-cut indictment was the role they played in the larger strategy of deterrence. Shultz and Schelling both see the use of nuclear weapons as catastrophic, but they differ on a long-term strategy to prevent their use.
Fourth, there is the question of deterrence, which is the hardest moral case. While moral in only the most marginal sense, it stood, paradoxically, as the final barrier against catastrophe during the cold war. Shultz and his coauthors believe that the end of the cold war has significantly decreased the previously unique role of deterrence, and thus the need for nuclear weapons. Schelling thinks stability—not abolition—is perhaps the best a complex world can hope for.
Fifth, at the heart of the Shultz–Schelling divide is a calculation of risk. What kind of risks should we run in the post–cold war, post–9/11 world? World politics is permeated by risk-taking, and strategic doctrine is based on an assessment of threats and risks. Moral analysis of jus in bello continually assesses targeting doctrine in terms of risks to civilians. The Shultz team states its basic premise about risk this way: “The four of us believe that reliance on nuclear weapons for deterrence is becoming increasingly hazardous and decreasingly effective.”Footnote 33 Schelling is equally clear about relative risks: “This nuclear quiet should not be traded away for a world in which a brief race to reacquire nuclear weapons could become every former nuclear state's overriding preoccupation.”Footnote 34
How best to summarize the state of the debate about GTZ? Both sides are deeply committed to a world without nuclear use of any kind; they disagree about whether a world without nuclear weapons is the best road to that goal. The calculation of risk is about the short and long term: what seems relatively stable today may in fact not be reasonably tenable over the long term. The effectiveness of deterrence is no easier to judge in this end-game analysis than it was at the height of the cold war. Neither side in this debate would forsake it quickly, but they are divided on its long-term utility. And both sides acknowledge the terrorist threat, but neither side considers it as pressing as dangers emanating from nuclear-armed states and the threat of proliferation to other states.
The moral literature of the past only gets us part way in assessing the GTZ proposal. Even for those who provided moral support for deterrence during the cold war, that support was usually tied to the objective (or hope or prayer) for the elimination of the threat posed by nuclear weapons. That background leads, I think, to support for the Shultz et al. proposal with the risk it entails. At the same time, any moral analysis of nuclear use directs one to support Schelling's emphasis on the nonuse tradition and all that can be done to reinforce it. I would argue that the assessment of deterrence must take place on three levels: its utility for relations between the United States and Russia is high; its utility in a multipolar world is far more complex but may be moderate; and its utility regarding terrorist threats is low but may not be nil. In all of these cases, even in the post–cold war era, the moral tests of jus in bello still apply to any deterrence policy. Moreover, the obligation to address the inequity critique is a serious one, and should be accomplished principally through lessening the way nuclear possession affects the status of states in nonmilitary matters. My belief is that we should pursue the proposals put forward by Shultz and his coauthors, but also be aware of possible unintended consequences in pursuing nuclear zero (Schelling's warning). We also need to strengthen the tradition of nonuse, and work to realize the arms control objectives supported by the vast majority of the world, including those objectives of many states that do not have nuclear weapons but are vulnerable to their effects.
A global ethic will have to address nuclear weapons as long as they exist. At the same time, these weapons no longer play the singularly dominant role they did in world politics for fifty years. Issues like the ethics of globalization, global poverty, and human rights now share center stage with nuclear weapons, the dangers of which have haunted the globe since 1945.
