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Tempting FateWhy Nonnuclear States Confront Nuclear Opponents$

Paul C. Avey

Print publication date: 2019

Print ISBN-13: 9781501740381

Published to Cornell Scholarship Online: May 2020

DOI: 10.7591/cornell/9781501740381.001.0001

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(p.1) Introduction
Tempting Fate

Paul C. Avey

Cornell University Press

Abstract and Keywords

This introductory chapter discusses the factors which lead nonnuclear weapon state (NNWS) decision makers to discount the prospects for nuclear use and be willing to challenge or resist a nuclear-armed opponent. The NNWS is able to act because it can take advantage of various strategic and material inhibitions against the use of nuclear arms to minimize the likelihood of a nuclear strike. In essence, the NNWS identifies red lines and gambles that, by its not crossing those lines, the costs of nuclear weapon use for the nuclear-armed opponent will outweigh the benefits. The precise strategies available and pursued by the NNWS will vary across cases. In general, though, the more militarily capable the NNWS is relative to the nuclear weapon state (NWS), the more difficult it will be for the NNWS to reduce the incentives for nuclear strikes. This forces a powerful NNWS to behave in a consistently constrained manner, and wars in nuclear monopoly will tend to occur only in the face of large power asymmetries favoring the NWS. This book's argument thus shows that nuclear weapons are neither irrelevant, as some argue, nor do they dictate state behavior. Ultimately, there are a variety of tools available to an NNWS to challenge, resist, and even win limited victories in a war against nuclear opponents.

Keywords:   nonnuclear weapon state, nuclear use, nuclear arms, nuclear strike, nuclear weapons, nuclear weapon state, nuclear monopoly, state behavior

Surveying the devastation in Japan after World War II, the United States Strategic Bombing Survey concluded that “no more forceful arguments for peace and for the international machinery of peace than the sight of the devastation of Hiroshima and Nagasaki have ever been devised.”1 The world quickly sought to make sense of the “absolute weapon.”2 Yet the power of the two bombs unleashed in 1945 would pale compared to the thermonuclear variants that would follow. The sheer speed and destructiveness of nuclear arms seemed to constitute a “nuclear revolution,” destined to upend international politics.3 Any country that lacked a nuclear arsenal would find itself vulnerable, unable to prevent becoming the target of a nuclear strike by threatening retaliation on the same scale.

Despite these weapons’ awesome power, though, countries without nuclear arms have not shied away from challenging and resisting nuclear-armed states. In 1948, less than three years after the United States had demonstrated its willingness to use nuclear weapons, the Soviet Union blockaded Berlin, directly challenging the American nuclear monopoly. The Soviets then stood firm for nearly a year against US efforts to undermine that blockade. Two years later, the young People’s Republic of China attacked US troops in Korea. Egypt and Syria combined to launch a massive assault on Israeli forces in October 1973. Iraq ignored US threats in 1990, and Serbia did likewise in 1999. In 1979, nonnuclear Vietnam fought a war against nuclear-armed China. The list goes on. According to one widely used conflict list, there have been sixteen wars between nuclear weapon states and nonnuclear weapon states from 1945 to 2010 and hundreds of lower-level militarized disputes. During that same period there were nineteen wars between states with no nuclear weapons. In other words, wars in which one side holds a nuclear monopoly occur about as often as those between states where neither side has nuclear weapons. Moreover, the nonnuclear weapon state (NNWS) frequently starts the trouble. In other cases, (p.2) the NNWS could have ceded to the demands of the nuclear weapon state (NWS) without giving up its rule or territory. Instead, it resisted.4

Why has the “absolute weapon” so frequently failed to impress states without it? This type of conflict is puzzling for both deterrence and compellence explanations. Bernard Brodie, whose early writings served as the foundation for thinking about nuclear politics, and whom nuclear strategist and Nobel laureate Thomas C. Schelling called “the dean of us all,” wrote that “certainly a monopoly of atomic bombs would be a sufficiently clear definition of superiority to dissuade the other side from accepting the gage of war unless directly attacked.”5 After the Cold War, Robert A. Pape argued that “when nuclear capabilities are completely one-sided … if the coercer’s capability is relatively unlimited, coercive success is virtually assured.”6 Addressing the United States specifically, James J. Wirtz highlights that theory predicts without “the constraints of mutual assured destruction or in some cases the possibility of even weak retaliation in kind, the United States and its allies should enjoy great success in deterring weaker states or compelling them to comply with their wishes.”7

In perhaps the most important statement on the nuclear revolution, Robert Jervis argued that mutual vulnerability induced restraint.8 He recognized that if one party gained a nuclear first-strike capability—if one side could completely eliminate the opponent’s arsenal—the situation would be vastly different. Yet his key insight that vulnerability induces caution can be applied to nuclear monopoly. The extreme vulnerability of an NNWS facing a nuclear opponent should encourage restraint. That danger should deter the NNWS from acting against the NWS. To be sure, the NWS might use nuclear weapons as a shield with which to conduct aggression against its hapless nonnuclear-armed opponents.9 Yet even then states without nuclear weapons should give in to all but the most extreme demands rather than risk a conflict in an environment of intense vulnerability.

A number of studies support these theoretical expectations by showing that nuclear superiority has historically provided political benefits. These include both deterrence (preventing an adversary from acting) and compellence (causing an adversary to change its behavior).10 Historian Marc Trachtenberg and political scientists Keir Lieber and Daryl Press have all found that US nuclear advantages relative to the Soviet Union in the early Cold War provided significant benefits during crises.11 Beyond the American case, Kyle Beardsley and Victor Asal argue that states with nuclear weapons facing nonnuclear opponents tend to prevail—by which they mean “either gaining concessions or having an opponent back down from its demands”—and prevail quickly. As they conclude, “the immense damage from the possibility of [nuclear] escalation is enough to make an opponent eager to offer concessions. Asymmetric crises allow nuclear states (p.3) to use their leverage to good effect.”12 Erik Gartzke and Dong-Joon Jo show that nuclear weapons provide broad bargaining advantages to their possessors.13 And Matthew Kroenig finds that states with larger nuclear arsenals than their opponents tend to win crises. As he puts it, “States in a position of nuclear superiority are more likely to issue compellent threats and to achieve compellent success.”14 If correct, then complete asymmetry in nuclear capabilities should provide substantial benefits.

Even those that contend nuclear weapons are poor tools for compellence generally accept that nuclear weapons are nevertheless useful for deterrence. Thus, Matthew Furhmann and Todd Sechser argue that the “ability to destroy does not necessarily convey the ability to [compel],” but add that nuclear weapons are “useful for deterrence … as weapons of self-defense, they are irreplaceable.”15 Indeed, they find that simply having an alliance with a nuclear-armed state provides benefits against would-be challengers.16 If an alliance with a nuclear state helps, one would expect that actual possession of a nuclear weapon would deter nonnuclear opponents.17

The coercive benefits of nuclear weapons are also at the center of strategic explanations for nuclear proliferation. According to these arguments, states facing large security threats will seek nuclear weapons. Such arguments therefore rest on the view that nuclear monopoly matters.18 If a nonnuclear state faces a nonnuclear opponent with superior conventional capabilities, then building a nuclear arsenal to manufacture a condition of nuclear monopoly can offset that danger and provide bargaining leverage. Conversely, if a nonnuclear state faces a nuclear-armed opponent, then acquiring a nuclear arsenal is beneficial because it eliminates nuclear monopoly. That allows the formerly nonnuclear state to deter nuclear strikes and counter efforts at nuclear blackmail. As Mao Zedong noted in 1956, China needed a nuclear weapon because “in today’s world, if we don’t want to be bullied, then we cannot do without this thing.”19 In other words, nuclear monopoly provided a potential compellent advantage to China’s nuclear-armed opponents that Mao sought to offset.

In sum, theory and evidence from a wide range of studies make NNWS belligerency toward nuclear rivals puzzling. Why, then, do states without nuclear weapons confront nuclear-armed opponents? A simple explanation would be that these conflicts occurred because no one believed nuclear weapons would be used. To begin with, I show that nonnuclear weapon states frequently did take their opponents’ nuclear arsenal into consideration. Moreover, such an explanation is unsatisfying because it does not answer the more interesting questions: why would leaders believe that nuclear weapons would not be used in certain situations? What factors lead NNWS decision makers to discount the prospects for nuclear use and be willing to challenge or resist a nuclear-armed opponent?

(p.4) The Argument

I argue that the nonnuclear weapon state is able to act because it can take advantage of various strategic and material inhibitions against the use of nuclear arms to minimize the likelihood of a nuclear strike. In essence, the NNWS identifies red lines and gambles that, by its not crossing those lines, the costs of nuclear weapon use for the nuclear-armed opponent will outweigh the benefits. The precise strategies available and pursued by the NNWS will vary across cases. In general, though, the more militarily capable the NNWS is relative to the NWS, the more difficult it will be for the NNWS to reduce the incentives for nuclear strikes. This forces a powerful NNWS to behave in a consistently constrained manner, and wars in nuclear monopoly will tend to occur only in the face of large power asymmetries favoring the NWS. My argument thus shows that nuclear weapons are neither irrelevant, as some argue, nor do they dictate state behavior. There are a variety of tools available to an NNWS to challenge, resist, and even win limited victories in a war against nuclear opponents.

States without nuclear weapons can focus on raising the costs or lowering the benefits of nuclear use for the NWS. There are real material and strategic costs to using nuclear weapons that constrain nuclear-armed states. These include the possibility that nuclear use destroys valuable objectives, harms friends or neutral states, generates diplomatic backlash from those not directly affected, expands a conflict to include new actors, or encourages nuclear proliferation. The NNWS can manipulate many of these factors in different situations to further raise the costs of nuclear use. For instance, the NNWS may seek out third parties to restrain the nuclear-armed opponent. The greater the danger to the NWS, the larger the benefits of using nuclear weapons, though. As benefits go up, a set of costs that were sufficient to dissuade nuclear use at one point may no longer do so. The NNWS can therefore also prosecute the conflict in a way that it believes will not create large dangers for the nuclear-armed opponent. This lowers the stakes for the NWS and reduces the likelihood of a nuclear strike. The key for the NNWS is to act so that some level of costs from using nuclear weapons sufficiently outweighs the benefits. I discuss these costs and benefits of nuclear use as well as NNWS strategies in much more detail in the next chapter.

The stronger the NNWS is, the more constrained it will have to be; the weaker the NNWS, the more options it can pursue, subject to its own conventional limitations. The claim that wars are more likely when the NNWS is conventionally weak is counterintuitive. Yet the basic logic is that the larger the conventional threat, the greater danger the NNWS poses and the fewer conventional options the NWS has to offset that danger.20 This raises the benefits of nuclear strikes for the NWS. As such, a powerful (p.5) NNWS must sharply limit its behavior to signal restraint and reduce the incentives for nuclear strikes. This is not to claim that it is great to be weak. A weak NNWS faces its own challenges and must weigh the likelihood of success in a conventional confrontation. Numerous factors aside from nuclear weapons will influence whether a militarily weaker NNWS will act or escalate during a conflict. The point is rather that a conventionally weak NNWS can fight a war against a nuclear opponent if it believes it has a plausible pathway to a favorable settlement precisely because it poses a smaller overall danger to the NWS. Because the NNWS poses a smaller danger, the benefits to the NWS of using its nuclear weapons are lower. This in turn makes it more likely that the costs of nuclear weapons use will outweigh the benefits. In other words, a militarily powerful NNWS must behave very cautiously; a militarily weak NNWS has more room to maneuver.

My argument leads to four main predictions. First, wars involving a conventionally powerful NNWS relative to its nuclear-armed opponent should be rare. Those wars that do occur in nuclear monopoly will tend to be fought between states with large conventional military disparities in favor of the nuclear-armed state. Second, the NWS should not face major dangers to its territorial integrity, critical military assets, and regime survival during wars in nuclear monopoly. Third, during political disputes, the NNWS leadership will focus on strategic factors that it believes will result in the NWS deciding the costs of nuclear use outweigh the benefits. Finally, my argument predicts that the NNWS should then act in a consistent manner, confronting the nuclear opponent in a way that limits the incentives for the NWS to execute a nuclear strike.

My argument addresses the conduct of political disputes and wars rather than which side starts the conflict. First, as outlined above, a large amount of theory and evidence suggests that nuclear monopoly provides coercive—that is, both deterrence and compellence—benefits. Yet conflict in nuclear monopoly is fairly common. My argument seeks to address both aspects of this puzzle.

Second, the NNWS faces the prospect of nuclear strikes when it elects to challenge rather than accept an undesired status quo and when it refuses to make concessions necessary to avoid a fight.21 This is not to claim there is no meaningful distinction between deterrence and compellence. It is likely more difficult to get an adversary to act rather than not act. As Kroenig points out, though, “it is one thing to argue … that compellence is more difficult than deterrence. It is quite another to claim … that nuclear weapons do not influence compellence at all.”22 The relationship between many of the costs of nuclear strikes for the NWS is contingent on the nature of the dispute and proposed consequences. For instance, both a deterrent and compellent threat that promise to overthrow a government and liberate its people for noncompliance with a demand generate the (p.6) same costs to the NWS for nuclear use, namely that such a strike would harm the people to be liberated. To be sure, it would be unsurprising that an NNWS would, to borrow from Brodie, accept the gage of war if suddenly attacked. Yet in most cases there were clear opportunities for the NNWS to avoid a fight.

Third, many disputes contain elements of both compellence and deterrence, with different actors making the first move at different points in the dispute. Kelly Greenhill and Robert Art highlight that “compellent actions are often undertaken in a crisis by a coercer in order to shore up its deterrent posture.”23 Additionally, Trachtenberg points out that in “the real world … wars are often not simply ‘started’ by one side, and the distinction between defender and attacker can be very problematic.”24 For instance, Iraq invaded Kuwait knowing it would invite some form of US response and then resisted US demands. Focusing on the dispute, rather than its initiation, shows how the shadow of nuclear weapons influenced Iraqi decision making over the course of the conflict. In several cases examined in this book, NWS policies intentionally or unintentionally created intolerable situations for the NNWS, blurring the line between offensive and defensive action. Relatedly, different conflict lists apply different criteria for initiation, and the authors themselves identify reasons one could code a dispute multiple ways.25 Defining the status quo is often problematic, particularly in disputes where it is in flux. The participants themselves will frequently disagree on what constitutes the status quo. “What one considers an innocent deterrent,” writes Richard Betts, “the other may see as a pernicious compellent.”26

I limit the scope of my study to situations where there is a political dispute between states. I avoid cases where an NNWS takes no action at all because it is so weak that it lacks any options to redress its grievances. In addition, if the NNWS has few interests at stake in an issue or no disagreement at all with a nuclear-armed state, then my argument does not apply. If the NNWS had little incentive to act in the first place, then it does not matter much if the NNWS possessed remarkably effective strategies to minimize the likelihood of a nuclear strike.

Previous studies suggest that in asymmetric conflict the weaker party will possess strong motivations to act.27 In the cases that I examine, the nonnuclear weapon states were highly resolved. In many of the cases the underlying political trends or actions by the nuclear-armed state were directly or indirectly threatening to the NNWS, which led to that high resolve. For example, US policies toward Germany following World War II created major concerns in the Soviet Union. With those concerns came an intense interest in reversing those policies. Similarly, the status quo facing Egypt after the Six Day War proved intolerable to Egyptian leaders. As I show, though, high resolution alone was not sufficient to cause NNWS leaders to ignore nuclear weapons.

(p.7) At the same time, the cases I examine in detail are ones in which the NWS had a demonstrated interest. Though in some cases the NNWS may believe the NWS will not act at all, and therefore discount nuclear weapons, in many it is clear that both sides have interests at stake. For instance, in 1950 the United States was already fighting in Korea when China intervened. One could doubt American commitment to the Korean Peninsula in the spring of 1950; one could not by the fall of the same year. In 1973 Israel had already fought to acquire (1967) and then hold on to (1969–1970) the Sinai Peninsula. The key is that the NNWS avoids posing a major danger to the NWS’s survival or creating a situation that can lead to large additional losses beyond the immediate dispute.

This book focuses, then, on how the NNWS probes the limits of the nuclear shadow, and how conventional military forces influence the likelihood for escalation. In practical terms, this means that the universe of cases to which this argument applies is not all possible interstate interactions but rather existing disputes. In social science terminology, an NNWS has already “selected into” some form of confrontation with a nuclear-armed opponent by challenging or resisting the NWS. I do not seek to explain the underlying factors that cause an NNWS to oppose an NWS in the first place. As noted, existing research suggests that weak actors who select into conflicts are likely to be highly resolved and have some baseline ability to act. These expectations are borne out in the case studies discussed in this book, with the NWS pursuing policies that create large strategic and domestic problems for the NNWS that then contribute to NNWS determination to act. However, I do not examine cases where nothing at all happened to fully demonstrate that states without an intense interest and baseline ability to act do in fact not do so. My argument instead accounts for the planning and behavior during disputes, including those few that escalate to wars. Despite these limitations, this book nevertheless covers a large number of important cases.

Implications for Scholarship and Policy

Understanding confrontations in nuclear monopoly has important implications for scholars and policy makers. To begin with, it helps clarify the role that nuclear weapons play in international politics. How far does the nuclear shadow extend? Much of what we know about the role that nuclear weapons play in disputes is limited to when both sides have them. This is not surprising, given the reasonable focus on the US-Soviet nuclear standoff during the Cold War. Today a great deal of attention goes to the nuclear relationships between the United States and China and between India and Pakistan.28 Even work that explicitly deals with nuclear asymmetry often focuses on cases when one country has a large qualitative or quantitative advantage over another nuclear-armed power.29

(p.8) The core claims of the nuclear revolution build from situations when both sides possess nuclear weapons. According to these arguments, mutual nuclear vulnerability makes crises and war unlikely, favors the preservation of the status quo, and ameliorates the security dilemma.30 In short, mutual vulnerability reduces many of the traditional external pressures in international politics. This situation is thought to be relatively durable because it is difficult for any state to gain a meaningful advantage against a nuclear-armed opponent. These claims were never universally accepted.31 Some argued the political effects of nuclear weapons were oversold, others that nuclear advantages could be made meaningful, and still others that normative conditions generated discourses that led nuclear-armed opponents to internalize mutual deterrence as the appropriate behavior for their status.32 Recent work by historians and political scientists using a variety of methods and armed with access to new archival and quantitative sources has further qualified and challenged several of these contentions.33

The nuclear revolution nevertheless offers a plausible account for some basic observations. Most notably, joint nuclear possession seems to deter nuclear strikes and reduces the chance for major war between two nuclear-armed states. Fortunately, there has yet to be a single instance of nuclear use by one nuclear power against another. There have also been, at most, two minor conventional wars directly between nuclear-armed states: China–Soviet Union in 1969 and India–Pakistan in 1999.

The stability-instability paradox can help explain why low-level conflict continues.34 The basic argument is that two nuclear-armed states are mutually deterred from using their nuclear arsenal and thus freed to fight low-level conventional wars and stumble into crises. This potential limitation of the nuclear revolution depends completely (by definition) on joint nuclear possession, thereby excluding cases of nuclear monopoly.

Left unexplained in these formulations is conflict in nuclear monopoly. Yet, as noted above, this type of conflict poses a puzzle for many existing explanations of nuclear politics. This book contributes to the understanding of the role of nuclear weapons in international politics by focusing exclusively on the comparatively understudied dynamics of nuclear monopoly, joining a small number of works that deal directly or indirectly with conflict in that context. It builds on, extends, and challenges portions of these studies that address aspects of NNWS behavior. I do not claim to provide the only explanation for the dynamics of nuclear monopoly. My aim is more limited: to expand on existing treatments to provide a fuller explanation for conflict in nuclear monopoly. To that end, I turn now to the relation between my argument and some of the most prominent studies in this area.

Insights from normative arguments help explain conflict in nuclear monopoly. By themselves, however, they are at best incomplete. The basic (p.9) normative claim is that states do not use nuclear weapons because there is a norm that arose over time proscribing nuclear use.35 As a result, NNWS leaders do not take nuclear use seriously and feel free to confront a nuclear-armed opponent.36 As a complete explanation for conflict in nuclear monopoly, what I term the “strong norms” claim, this argument is seriously flawed. Referencing the nuclear nonuse norm, T. V. Paul asks rhetorically: “If there existed neither an explicit legal ban nor a deterrent capability to prevent possible nuclear retaliation, what else could explain the belief among decision makers of nonnuclear states that nuclear weapons would not be used against them in their impending conflict?”37 As I show, a great deal of other factors help explain decision making in nonnuclear states. To be fair, Paul recognizes that “other possible political and strategic constraints” may operate, though he does not develop these in any detail. Similarly, Michael Gerson writes that the reason states without nuclear weapons “are not intimidated by an opponent’s nuclear capabilities” is “due in part to the perceived impact of the ‘nuclear taboo.’”38 Yet there is no effort to explore the other “parts” that influence NNWS decision makers. Paul Huth and Bruce Russett argue that, at least in extended deterrence situations, NNWS leaders do not think nuclear use is credible because “normative inhibitions associated with this disproportion [of nuclear destruction] made it absurd to consider nuclear use a real possibility.”39

Others provide even fewer qualifications. In the most important book on the nuclear taboo, Nina Tannenwald concludes simply that “because of the taboo, a nuclear threat against a nonnuclear state is no longer credible.”40 The former US national security adviser McGeorge Bundy made a similar point when he noted that as a result of the tradition of nonuse, “no government without [nuclear] weapons needs to be easily coerced by nuclear threats from others, because both history and logic make it clear that no government will resort to nuclear weapons over less than a mortal question.”41 There is often little effort to demonstrate that NNWS leaders relied on normative factors; the mere fact of conflict is taken as evidence that the norm must be at work.

If the strong-norms claim is correct, NNWS leaders should simply identify nuclear nonuse norms as the reason that nuclear weapons would not be used and be willing to confront a nuclear-armed opponent. Leaders may not even discuss their opponent’s nuclear status at all if they have internalized the belief that norms constrain nuclear use. The taboo should also operate regardless of relative conventional capabilities. The case studies and pattern of war in nuclear monopoly makes clear that these claims do not hold.

Yet normative factors are not irrelevant, even if they are not a comprehensive explanation for conflict. NNWS leaders may believe that international opinion might lead to negative consequences for the NWS in the form of diplomatic blowback, sanctions, or even active support for the (p.10) NNWS following nuclear use. This would particularly be the case if nuclear use resulted in large numbers of civilian deaths. Indeed, this is consistent with views that harming civilians—even by conventional means—should be avoided.42 NNWS leaders at times highlight such considerations when deciding how to confront nuclear opponents. They may even attempt to manipulate international condemnation to minimize the risks of nuclear strikes. They do so in the belief that this type of negative blowback will create a strategic disincentive for nuclear use even if the NWS was willing to internally set aside normative considerations.43 My argument incorporates this insight by highlighting how evolving norms can generate strategic consequences that the NNWS can leverage. In short, the NNWS can use norms instrumentally. The focus on normative factors occurs alongside consideration of material and strategic issues.

A number of studies highlight how various costs of nuclear use, force structures, and interests influence the effects of nuclear weapons. For instance, Sechser and Fuhrmann identify several similar costs to explain nuclear compellence failures.44 Vipin Narang shows how nuclear-armed states facing conventionally powerful militaries are more likely to see the benefits of nuclear use as outweighing the costs and adopt corresponding force postures and doctrines. Moreover, wars in those situations are unlikely to occur.45 Still others contend that states will confront a nuclear-armed opponent when they have a much larger stake than their opponent does in the issue.46

I go beyond these existing studies in several ways. First, I focus exclusively on these dynamics in nuclear monopoly. As such, I consider additional costs and benefits of nuclear use and show that many of the costs others identify have implications for both deterrence and compellence when only one side has nuclear weapons. Second, this book demonstrates that wars involving NNWS militaries with strong conventional capabilities relative to their nuclear opponents will be rare in nuclear monopoly, regardless of the specific force posture. Most importantly, I am able to demonstrate in a number of cases that NNWS decision makers explicitly considered various costs and benefits of nuclear use across discrete types of nuclear deployments. Finally, I show that even if the NNWS has a greater relative interest in the issue, that does not mean it ignores the possibility of nuclear use.

Beyond nuclear politics, some perspectives claim that power asymmetries dampen conflict by clarifying who will win. For example, Geoffrey Blainey argues that many wars start because both sides believe they could win.47 That type of mutual optimism is more likely when both sides have similar capabilities, because each can entertain hopes of victory. This insight is at the center of the influential bargaining model of war, which, as Dan Reiter notes, predicts conflict when there is “disagreement over the balance of power.”48 War thus becomes less likely when power asymmetries (p.11) increase, because the balance of power is clear. Numerous quantitative studies find support for the relationship that war is less likely as power imbalances increase.49 The inverse prediction is also true, that states are unlikely to fight if they expect to lose. These dynamics still exist in nuclear monopoly, with many weak states seeking to avoid war because they would lose, but they are counterbalanced by the reluctance of militarily powerful nonnuclear states to fight against an NWS.

Turning to more practical considerations, the world is no longer dominated by the superpower standoff between the United States and the Soviet Union. Many actual and potential conflicts involve states without nuclear weapons in confrontations with states that have nuclear weapons. Since 2000 alone, the United States has used or threatened force against Iraq, Iran, Libya, North Korea (nonnuclear prior to 2006), and Syria. Russia has invaded the territory of two of its nonnuclear neighbors. Israel continues to have serious disputes with actors, all nonnuclear, along its border. Although nuclear use in any of these conflicts is unlikely, any time conflict occurs, the risks of nuclear use increases. Understanding the dynamics of these conflicts can help minimize the chances that the world witnesses its first nuclear detonation in combat since 1945. A better understanding of conflict in nuclear monopoly is thus hardly a trivial matter.

If states without nuclear weapons simply ignore such weapons, then nuclear-armed states face an uphill battle convincing such opponents that nuclear weapons might actually be used. This can create a space for NWS policy entrepreneurs who argue for potentially dangerous policies to demonstrate credibility, such as delegating launch authority, forward deploying nuclear assets, or investing in a new generation of more “usable” nuclear weapons. A nuclear force rendered virtually incredible might also cause adversaries to misinterpret red lines for actual nuclear use. Such miscalculation could result in catastrophe.

Finally, if nuclear weapons only deterred nuclear strikes, with few other political consequences, this would strengthen calls for global nuclear-zero arguments.50 After all, what is the point of keeping a weapon that everyone knows no state will ever use? Ridding the world of nuclear weapons would achieve the same effect as mutual nuclear deterrence—preventing someone from striking you with a nuclear bomb—without the risks of nuclear accidents.

The rest of this book develops my argument and assesses the predictions against the historical record. I then return to broader implications for nuclear strategy and politics in the conclusion.


(1.) “U.S. Strategic Bombing Survey: The Effects of the Atomic Bombings of Hiroshima and Nagasaki,” June 19, 1946, President’s Secretary’s File, Truman Papers, https://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/pdfs/65.pdf.

(2.) Bernard Brodie, ed., The Absolute Weapon: Atomic Power and World Order (New York: Harcourt Brace, 1946).

(3.) Robert Jervis, The Meaning of the Nuclear Revolution: Statecraft and the Prospect of Armageddon (Ithaca, NY: Cornell University Press, 1989).

(4.) The Correlates of War data code the NNWS as starting the war or underlying militarized interstate dispute (MID) half the time: Korean War, 1950; Suez War, 1956; Six Day War, 1967; War of Attrition, 1969; October War, 1973; Falklands War, 1982; War over Angola, 1987; Gulf War, 1991. I found 657 MIDs between two states, or dyads, when only one possessed nuclear weapons. Although there are a number of challenges to coding initiation, as I discuss below, using the MID coding, the NNWS initiated approximately 36 percent of disputes. That number increases to 43 percent when including an NNWS that joined on the initiator’s side. Using the International Crisis Behavior (ICB) dataset, I found 119 overall crises (many containing multiple dyads) where only one side had nuclear weapons from 1946 to 2015. ICB identified the NNWS as the “triggering entity” in approximately 61 percent of the 87 cases that had a single state actor as the triggering entity. War data are from the Dyadic Inter-state War Data at http://www.correlatesofwar.org/data-sets/COW-war. MID data are from the Dyadic MID data version 3.1, at http://www.correlatesofwar.org/data-sets/MIDs. See Zeev Maoz, Paul L. Johnson, Jasper Kaplan, Fiona Ogunkoya, and Aaron Shreve, “The Dyadic Militarized Interstate Disputes (MIDs) Dataset Version 3.0: Logic, Characteristics, and Comparisons to Alternative Datasets,” Journal of Conflict Resolution 63, no. 3 (2019): 811–35. ICB data are from the Dyadic-Level Crisis Data and System-level data, Version 12, at https://sites.duke.edu/icbdata/data-collections/.

(5.) Brodie, Absolute Weapon, 85. Brodie relegated the comment to a footnote. For the Schelling quote see Robert Ayson, Thomas Schelling and the Nuclear Age: Strategy as Social Science (London: Routledge, 2004), 114.

(6.) Robert A. Pape, Bombing to Win: Air Power and Coercion in War (Ithaca, NY: Cornell University Press, 1996), 38. Pape highlights various constraints on nuclear use but does not develop (p.182) them. See also the discussion in John J. Mearsheimer, The Tragedy of Great Power Politics, 2nd ed. (2001; New York: W. W. Norton, 2014), 129–30.

(7.) James J. Wirtz, “Conclusions,” in Complex Deterrence: Strategy in the Global Age, ed. T. V. Paul, Patrick M. Morgan, and James J. Wirtz (Chicago: University of Chicago Press, 2009), 322. Wirtz adds that this expectation is frequently challenged, calling traditional deterrence arguments into question.

(8.) Robert Jervis, The Meaning of the Nuclear Revolution: Statecraft and the Prospect of Armageddon (Ithaca, NY: Cornell University Press, 1989), chap. 1. See also Kenneth N. Waltz, “Nuclear Myths and Political Realities,” American Political Science Review 84, no. 3 (September 1990): 731–45.

(9.) Mark S. Bell and Nicholas L. Miller argue that states frequently expand their interests upon acquiring nuclear weapons. This line of argument again points to the general belief that nuclear weapons convey coercive benefits. See Mark S. Bell and Nicholas L. Miller, “Questioning the Effects of Nuclear Weapons on Conflict,” Journal of Conflict Resolution 59, no. 1 (February 2015): 74–92, and Mark S. Bell, “Beyond Emboldenment: How Acquiring Nuclear Weapons Can Change Foreign Policy,” International Security 40, no. 1 (Summer 2015): 87–119.

(10.) Throughout this book I follow Thomas C. Schelling and use the term “coercion” to include both deterrence and compellence. In both cases a state attempts to influence an opponent’s behavior: either to not act (deterrence) or to act (compellence) when the adversary would prefer the opposite. Thomas C. Schelling, Arms and Influence (New Haven, CT: Yale University Press, 1966). See also Robert J. Art, “To What Ends Military Power?,” International Security 4, no. 4 (Spring 1980): 3–35; and Robert J. Art and Kelly M. Greenhill, “Coercion: An Analytical Overview,” in Coercion: The Power to Hurt in International Politics, ed. Kelly M. Greenhill and Peter Krause (Oxford: Oxford University Press, 2018).

(11.) Marc Trachtenberg, “The Influence of Nuclear Weapons in the Cuban Missile Crisis,” International Security 10, no. 1 (Summer 1985): 137–63; Daryl G. Press, Calculating Credibility: How Leaders Assess Military Threats (Ithaca, NY: Cornell University Press, 2005); Keir A. Lieber, War and the Engineers: The Primacy of Politics over Technology (Ithaca, NY: Cornell University Press, 2005).

(12.) Kyle Beardsley and Victor Asal, “Winning with the Bomb,” Journal of Conflict Resolution 53, no. 2 (April 2009): 282, 297.

(13.) Erik Garzke and Dong-Joon Jo, “Bargaining, Nuclear Proliferation, and Interstate Disputes,” Journal of Conflict Resolution 53, no. 2 (April 2009): 209–33.

(14.) Matthew Kroenig, The Logic of American Nuclear Strategy: Why Strategic Superiority Matters (Oxford: Oxford University Press, 2018): 123; Matthew Kroenig, “Nuclear Superiority and the Balance of Resolve: Explaining Nuclear Crisis Outcomes,” International Organization 67, no. 1 (January 2013): 141–71. For a review of studies that find nuclear-armed states are able to successfully compel opponents, see Todd S. Sechser and Matthew Fuhrmann, Nuclear Weapons and Coercive Diplomacy (Cambridge: Cambridge University Press, 2017), 7–8, 34–38.

(15.) Sechser and Fuhrmann, Nuclear Weapons and Coercive Diplomacy, 17, 15, 59. See also Todd S. Sechser and Matthew Fuhrmann, “Crisis Bargaining and Nuclear Blackmail,” International Organization 67, no. 1 (January 2013): 173–95. For general statements that nuclear weapons are useful for deterrence but not compellence see, for example, Waltz, “Nuclear Myths and Political Realities”; Jervis, Meaning of the Nuclear Revolution, esp. 29–35; Stephen Van Evera, Causes of War: Power and the Roots of Conflict (Ithaca, NY: Cornell University Press, 1999), 246. For evidence that a majority, but by no means all, American IR faculty and former national security policy makers share this view see Paul C. Avey, “MAD and Taboo: Expert Views on Nuclear Weapons,” paper presented at the 2018 annual meeting of the American Political Science Association.

(16.) Matthew Fuhrmann and Todd S. Sechser, “Signaling Alliance Commitments: Hand-Tying and Sunk Costs in Extended Nuclear Deterrence,” American Journal of Political Science 58, no. 4 (October 2014): 919–35. See also James D. Fearon, “Signaling versus the Balance of Power and Interests: An Empirical Test of a Crisis Bargaining Model,” Journal of Conflict Resolution 38, no. 2 (1994): 253–57.

(p.183) (17.) To be sure, nuclear weapons may generally provide states with deterrent benefits. That nevertheless leaves a large number of important exceptions that require an explanation. Those exceptions are the focus of this book.

(18.) The strategic-proliferation literature is large and disagrees on the precise conditions under which states will acquire nuclear weapons and the force structure they will ultimately construct. Nevertheless, these explanations share the key intuition that states seek nuclear weapons to enhance their security: to better deter and compel opponents. See, for example, Vipin Narang, Nuclear Strategy in the Modern Era: Regional Powers and International Conflict (Princeton, NJ: Princeton University Press, 2014); Nuno P. Monteiro and Alexandre Debs, “The Strategic Logic of Proliferation,” International Security 39, no. 2 (Fall 2014): 7–51; Gene Gerzhoy, “Alliance Coercion and Nuclear Restraint: How the United States Thwarted West Germany’s Nuclear Ambitions,” International Security 39, no. 4 (Spring 2015): 91–129; Nicholas L. Miller, “Nuclear Dominoes: A Self-Defeating Prophecy?,” Security Studies 23, no. 1 (January–March 2014): 33–73; Bradley A. Thayer, “The Causes of Nuclear Proliferation and the Utility of the Nuclear Non-proliferation Regime,” Security Studies 4, no. 3 (July–September 1995): 463–519.

(19.) M. Taylor Fravel and Evan S. Medeiros, “China’s Search for Assured Retaliation: The Evolution of Chinese Nuclear Strategy and Force Structure,” International Security 35, no. 2 (Fall 2010): 61.

(20.) For a similar point regarding disputes between two nuclear powers with asymmetric conventional capabilities see Jasen J. Castillo, “Deliberate Escalation: Nuclear Strategies to Deter or to Stop Conventional Attacks,” in Greenhill and Krause, Coercion, 293. Analysts have applied this basic point to other instances as well, notably US nuclear strategy in the Cold War against the Soviet Union when the latter possessed conventional superiority in Europe, as well as to nuclear-armed states facing overwhelming conventional adversaries today.

(21.) I thank a reviewer for raising this point.

(23.) Art and Greenhill, “Coercion,” 6. In addition to the specific quotes cited in this paragraph see Patrick M. Morgan, Deterrence Now (Cambridge: Cambridge University Press, 2003), 2–3; Maria Sperandei, “Bridging Deterrence and Compellence: An Alternative Approach to the Study of Coercive Diplomacy,” International Studies Review 8, no. 2 (June 2006): esp. 259–61.

(24.) Marc Trachtenberg, “Waltzing to Armageddon,” National Interest, Fall 2002, 147.

(25.) For instance, compare the initiator coding for wars from the Correlates of War Interstate War data with the list by Dan Reiter, Alan Stam, and Michael Horowitz. Specific cases are often contentious; Reiter et al. note that North Vietnam could plausibly be coded as starting the Vietnam War against the United States. Even cases where the NNWS is widely regarded as the initiator can follow very different paths. Both Argentina and Egypt “initiated” wars against a nuclear opponent. Argentina’s leaders launched an initially bloodless effort to capture the Falkland Islands, hoping that Britain would not react at all; Egyptian leaders sought to immediately engage Israeli forces in October 1973. Zeev Maoz, Paul L. Johnson, Aaron Shreve, Fiona Ogunkyoya, Jasper Kaplan, “Dyadic MID Codebook—Version 3.0,” May 24, 2018, 9. Dan Reiter, Allan C. Stam, and Michael C. Horowitz, “A Revised Look at Interstate Wars, 1816–2007: Appendix,” October 15, 2014, 18. Miscoding some cases is not problematic if the errors are (1) random and (2) there are a large number of observations. Interstate wars are rare events, and the number of nuclear-armed states few. When dealing with small numbers, changing the coding of even a few data points can easily lead to different results. On these points see Erik Gartzke, “An Apology for Numbers in the Study of National Security … if an Apology Is Really Necessary,” H-Diplo|ISSF Forum, no. 2 (2014): 82; Vipin Narang, “The Use and Abuse of Large-N Methods in Nuclear Studies,” H-Diplo|ISSF Forum, no. 2 (2014): 91–97; Alexander H. Montgomery and Scott D. Sagan, “The Perils of Predicting Proliferation,” Journal of Conflict Resolution 53, no. 2 (April 2009): esp. 310–13.

(26.) Richard K. Betts, Nuclear Blackmail and Nuclear Balance (Washington, DC: Brookings Institution, 1987), 6, see also 135–41.

(27.) James D. Fearon, “Domestic Political Audience Costs and the Escalation of International Disputes,” American Political Science Review 88, no. 3 (September 1994): 578; James D. Fearon, (p.184) “Signaling versus the Balance of Power and Interests: An Empirical Test of a Crisis Bargaining Model,” Journal of Conflict Resolution 38, no. 2 (June 1994): 246–48; Todd S. Sechser, “Goliath’s Curse: Coercive Threats and Asymmetric Power,” International Organization 64 (Fall 2010): 627–60; T. V. Paul, Asymmetric Conflicts: War Initiation by Weaker Powers (Cambridge: Cambridge University Press, 1994), 16–17; Phil Haun, Coercion, Survival, and War: Why Weak States Resist the United States (Stanford, CA: Stanford University Press, 2015), 33–34.

(28.) See, for example, Charles L. Glaser and Steve Fetter, “Should the United States Reject MAD? Damage Limitation and U.S. Nuclear Strategy toward China,” International Security 41, no. 1 (Summer 2016): 49–98; Caitlin Talmadge, “Would China Go Nuclear? Assessing the Risk of Chinese Nuclear Escalation in a Conventional War with the United States,” International Security 41, no. 4 (Spring 2017): 88–90; Sumit Ganguly, “Nuclear Stability in South Asia,” International Security 33, no. 2 (Fall 2008): 45–70; S. Paul Kapur, “India and Pakistan’s Unstable Peace: Why Nuclear South Asia Is Not Like Cold War Europe,” International Security 30, no. 2 (Fall 2005): 127–52; Vipin Narang, “Posturing for Peace? Pakistan’s Nuclear Postures and South Asian Stability,” International Security 34, no. 3 (Winter 2009/10): 38–78.

(29.) See, for example, Jan Ludvik, Nuclear Asymmetry and Deterrence: Theory, Policy and History (London: Routledge, 2017); Kroenig, “Nuclear Superiority”; Keir A. Lieber and Daryl G. Press, “The End of MAD? The Nuclear Dimension of U.S. Primacy,” International Security 30, no. 4 (Spring 2006): 7–44.

(30.) Jervis, Meaning of the Nuclear Revolution, chap. 1; Charles L. Glaser, Analyzing Strategic Nuclear Policy (Princeton, NJ: Princeton University Press, 1990); Waltz, “Nuclear Myths and Political Realities.”

(31.) Francis J. Gavin, Nuclear Statecraft: History and Strategy in America’s Atomic Age (Ithaca, NY: Cornell University Press, 2012), chap. 8.

(32.) For examples of each position see John Mueller, Atomic Obsession: Nuclear Alarmism from Hiroshima to Al-Qaeda (Oxford: Oxford University Press, 2010), 29–54; John Mueller, “The Essential Irrelevance of Nuclear Weapons: Stability in the Postwar World,” International Security 13, no. 2 (Fall 1988): 55–79; Colin S. Gray and Keith Payne, “Victory Is Possible,” Foreign Policy 39 (Summer 1980): 14–27; Nina Tannenwald, The Nuclear Taboo: The United States and the Non-use of Nuclear Weapons since 1945 (Cambridge: Cambridge University Press, 2007), 18–19, 30–38, 45, 370–74; Nina Tannenwald, “Stigmatizing the Bomb: Origins of the Nuclear Taboo,” International Security 29, no. 4 (Spring 2005): 41.

(33.) In addition to sources cited in notes 12–14 above see Gavin, Nuclear Statecraft; Francis J. Gavin, “Politics, History and the Ivory Tower–Policy Gap in the Nuclear Proliferation Debate,” Journal of Strategic Studies 35, no. 4 (August 2012): 573–600; Austin Long and Brendan Rittenhouse Green, “Stalking the Secure Second Strike: Intelligence, Counterforce, and Nuclear Strategy,” Journal of Strategic Studies 38, nos. 1–2 (2015): 38–73; Brendan R. Green and Austin Long, “The MAD Who Wasn’t There: Soviet Reactions to the Late Cold War Nuclear Balance,” Security Studies 26, no. 4 (October–December 2017): 606–41; Keir A. Lieber and Daryl G. Press, “The New Era of Counterforce: Technological Change and the Future of Nuclear Deterrence,” International Security 41, no. 4 (Spring 2017): 9–49. See also Mearsheimer, Tragedy of Great Power Politics, 128–33, 230–32.

(34.) Kenneth N. Waltz, Man, the State, and War: A Theoretical Analysis (New York: Columbia University Press, 1959), 236; Glenn H. Snyder, “The Balance of Power and the Balance of Terror,” in The Balance of Power, ed. Paul Seabury (San Francisco: Chandler, 1965), 184–201; Robert Rauchhaus, “Evaluating the Nuclear Peace Hypothesis: A Quantitative Approach,” Journal of Conflict Resolution 53, no. 2 (April 2009): 258–77. For a review see David J. Karl, “Proliferation Optimism and Pessimism Revisited,” Journal of Strategic Studies 34, no. 4 (August 2011): 619–41. For a critique see Jervis, Meaning of the Nuclear Revolution, 19–22.

(35.) See, for example, Tannenwald, Nuclear Taboo; Avner Cohen, “Nuclear Arms in Crisis under Secrecy: Israel and the Lessons of the 1967 and 1973 Wars,” in Planning the Unthinkable: How New Nuclear Powers Will Use Nuclear, Biological, and Chemical Weapons, ed. Peter R. Lavoy, Scott D. Sagan, and James J. Wirtz (Ithaca, NY: Cornell University Press, 2000), 104–24; George H. Quester, Nuclear First Strike: Consequence of a Broken Taboo (Baltimore: Johns Hopkins University Press, 2006); T. V. Paul, The Tradition of Non-use of Nuclear Weapons (Stanford, CA: Stanford (p.185) University Press, 2009); T. V. Paul, “Taboo or Tradition? The Non-use of Nuclear Weapons in World Politics,” Review of International Studies 36, no. 4 (October 2010): 853–63.

(36.) Tannenwald, Nuclear Taboo, 3, 372; Paul, Tradition of Non-use, chap. 7; T. V. Paul, “Power, Influence, and Nuclear Weapons: A Reassessment,” in The Absolute Weapon Revisited: Nuclear Arms and the Emerging International Order, ed. T. V. Paul, Richard J. Harknett, and James J. Wirtz (Ann Arbor: University of Michigan Press, 1998), 19–46; Peter Gizewski, “From Winning Weapon to Destroyer of Worlds: The Nuclear Taboo in International Politics,” International Journal 51, no. 3 (Summer 1996): 397–419; Paul Huth and Bruce Russett, “Deterrence Failure and Crisis Escalation,” International Studies Quarterly 32, no. 1 (March 1988): 29–45; Robert Farley, “The Long Shadow of the Falklands War, National Interest, September 8, 2014, http://nationalinterest.org/feature/the-long-shadow-the-falklands-war-11224?page=show.

(38.) Michael S. Gerson, “Conventional Deterrence in the Second Nuclear Age,” Parameters 39, no. 3 (Autumn 2009): 35.

(39.) Huth and Russett, “Deterrence Failure and Crisis Escalation,” 38, see also 34–35; Bruce Martin Russett, “Extended Deterrence with Nuclear Weapons: How Necessary, How Acceptable?,” Review of Politics 50, no. 2 (Spring 1988): 290.

(40.) Tannenwald, Nuclear Taboo, 372, see also 3. Tannenwald’s discussion of the role of normative and material considerations in accounting for nuclear-armed state decision making is much more nuanced; see esp. 53.

(41.) McGeorge Bundy, Danger and Survival: Choices about the Bomb in the First Fifty Years (New York: Random House, 1988), 588. Bundy did not expand on the tradition concept, but it contained a normative component; see 586–88.

(42.) Dianne Pfundstein Chamberlain, Cheap Threats: Why the United States Struggles to Coerce Weak States (Washington, DC: Georgetown University Press, 2016), 45–47. On American public opinion toward military actions that result in civilian deaths see Scott D. Sagan and Benjamin A. Valentino, “Revisiting Hiroshima in Iran: What Americans Really Think about Using Nuclear Weapons and Killing Noncombatants,” International Security 42, no. 1 (Summer 2017): 41–79.

(43.) They thus focus on the regulative rather than the constitutive aspects of the norm.

(45.) Narang, Nuclear Strategy in the Modern Era, chaps. 9–10; Vipin Narang, “What Does It Take to Deter? Regional Power Nuclear Postures and International Conflict,” Journal of Conflict Resolution 57, no. 3 (June 2013): 478–508; Vipin Narang, “Posturing for Peace?”

(46.) This draws on the basic issue of resolve discussed in “The Argument” section earlier in this chapter. I focus on existing political disputes in which both sides have demonstrated some level of resolve over the issue. A distinct but related claim is that once in a dispute, the weaker side compensates for lack of relative capability with intensity that occasionally allows it to prevail. My argument makes no claim about which side will win the conflict; I focus on the role nuclear weapons play in shaping the scope of the conflict. For discussions and applications to asymmetric conflict see Paul, Asymmetric Conflict, 16–18; Haun, Coercion, Survival, and War, 12–13, 36; Alexander L. George and Richard Smoke, Deterrence in American Foreign Policy: Theory and Practice (New York: Columbia University Press, 1974), 530–31, 550–61; Paul K. Huth, “Deterrence and International Conflict: Empirical Findings and Theoretical Debates,” Annual Review of Political Science 2 (1999): 34; Glenn H. Snyder and Paul Diesing, Conflict among Nations: Bargaining, Decision Making, and System Structure in International Crises (Princeton, NJ: Princeton University Press, 1977), 190, 456, 529. For an excellent overview of how different approaches treat resolve, see Chamberlain, Cheap Threats, 7–13.

(47.) Geoffrey Blainey, The Causes of War, 3rd ed. (London: Macmillan, 1988).

(48.) Dan Reiter, “Exploring the Bargaining Model of War,” Perspectives on Politics 1, no. 1 (March 2003): 33.

(49.) For example, Michelle Benson, “Extending the Bounds of Power Transition Theory,” International Interactions 33, no. 3 (2007): 211–15; William Moul, “Power Parity, Preponderance, and War between Great Powers, 1816–1989,” Journal of Conflict Resolution 47, no. 4 (2003): 468–89; A. F. K. Organski and Jacek Kugler, The War Ledger (Chicago: University of Chicago (p.186) Press, 1980). Many studies that include a proxy for relative power as a control variable in their analysis similarly find that increasing power asymmetries make war less likely.

(50.) David Cortright and Raimo Väyrynen, Toward Nuclear Zero (New York: Routledge, 2010), 91; James E. Doyle, “Why Eliminate Nuclear Weapons?,” Survival 55, no. 1 (2013): 7–34.