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Library of Congress Cataloging-in-Publication Data
Names: Kroenig, Matthew, author.
Title: The logic of American nuclear strategy : why strategic superiority matters / Matthew Kroenig.
Description: New York City : Oxford University Press, [2018] | Includes bibliographical references and index.
Identifiers: LCCN 2017035084 (print) | LCCN 2017058642 (ebook) | ISBN 9780190849191 (updf) | ISBN 9780190849207 (epub) | ISBN 9780190849184 (hardcover)
Subjects: LCSH: Nuclear weapons—Government policy—United States. | United States—Military policy. | Strategic forces—United States. | Strategy. Classification: LCC UA23 (ebook) | LCC UA23 .K783 2018 (print) | DDC 355.02/170973—dc23 LC record available at https://lccn.loc.gov/2017035084
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Printed by Sheridan Books, Inc., United States of America
Also by Matthew Kroenig
Author or Co-Author
A Time to Attack: The Looming Iranian Nuclear Threat
Exporting the Bomb: Technology Transfer and the Spread of Nuclear Weapons
The Handbook of National Legislatures: A Global Survey
Co-Editor
Nonproliferation Policy and Nuclear Posture: Causes and Consequences for the Spread of Nuclear Weapons
Causes and Consequences of Nuclear Weapons Proliferation
CONTENTS
Preface ix
Abbreviations and Acronyms xiii
Introduction 1
PART ONE THE ADVANTAGES OF NUCLEAR ADVANTAGES
1. Toward a New Theory of Nuclear Deterrence: The Superiority-Brinkmanship Synthesis Theory 15
2. Nuclear War Outcomes 39
3. The Correlates of Nuclear Crisis Outcomes 65
4. The Mechanisms of Nuclear Crisis Outcomes 81
5. Nuclear Deterrence and Compellence 114
PART TWO THE DISADVANTAGES OF NUCLEAR ADVANTAGES?
6. Strategic Stability 127
7. Arms Races 143
8. Nuclear Nonproliferation 159
9. The Defense Budget 178
Conclusion 188
Notes 207 Bibliography 233
Index 247
PREFACE
In the fall of 2008, I was settling in to my first semester as an assistant professor in the Department of Government at Georgetown University and teaching a course in my area of expertise, titled “Nuclear Weapons in World Politics.” Developing a new course is always challenging, and there were many memorable episodes from that first semester, but one in particular stands out.
I was discussing the requirements for successful nuclear deterrence and I explained to my students that once a country possesses a nuclear arsenal capable of a secure, second-strike (the ability to absorb a nuclear attack from an opponent and retain enough surviving warheads to respond with a devastating nuclear counterattack), then nuclear deterrence would hold. I also mentioned that, although academics are skeptical of the idea, many US policymakers believe that the United States’s possession of nuclear superiority over a rival, even above and beyond a mere second-strike capability, also contributes to deterrence.
Inevitably, one of my smart and curious students asked why.
I did not have an answer.
The politics of nuclear weapons was my area of expertise. It was a major part of the reason why I was hired at Georgetown. I had received a Public Policy and Nuclear Threats fellowship from the National Science Foundation during graduate school at the University of California at Berkeley and I had just spent a year as a postdoctoral fellow at the Managing the Atom Project at Harvard University. I had previously served as a military analyst at the Central Intelligence Agency and a strategist in the Office of the Secretary of Defense, where I had worked on issues of nuclear weapons and deterrence. I had a book and several articles on nuclear issues in the pipeline, accepted for publication in top scholarly outlets. I vividly recalled the reams of scholarship I had read on nuclear deterrence theory. Yet, I could not call to mind a single, clear explanation for why a strategic nuclear advantage might translate into a geopolitical advantage. If anyone should have been able to answer this question, it was me. But I was at a loss for words.
I eventually offered something about how a more robust nuclear force might be relevant to counterforce targeting in the event of a nuclear war, but the answer was deeply unsatisfying, even to myself. I was determined to learn more.
This book is the result of that initial curiosity.
The writing of this book was made possible by many institutions and individuals. I am fortunate to teach at Georgetown University and I am grateful to Georgetown’s senior leadership, Jack DeGioia, Robert Groves, Joel Hellman, Charles King, and Irfan Nooruddin, for providing me with a career at what I believe is the best institution in the world to be a political science professor. To my fellow international relations scholars at Georgetown, Anthony Arend, Andrew Bennett, Marc Busch, Daniel Byman, Victor Cha, Raj Desai, David Edelstein, Bruce Hoffman, Lise Howard, Robert Lieber, Keir Lieber, Charles Kupchan, Kathleen McNamara, Daniel Nexon, Abraham Newman, Nita Rudra, George Shambaugh, Elizabeth Stanley, Erik Voeten, and James Vreeland, thank you for setting a high bar and inspiring me to do better work every day.
In 2013, I accepted an affiliation as a senior fellow in the Brent Scowcroft Center on International Security at the Atlantic Council. Jon Huntsman, Frederick Kemp, Damon Wilson, Barry Pavel, and Magnus Nordstrom deserve credit for transforming the Atlantic Council from a small organization focusing on transatlantic issues into one of the largest, most diverse, and impactful nonpartisan foreign policy think tanks in Washington in less than a decade.
The book was completed with financial support from the Smith Richardson Foundation. Some of the work on this project was also conducted while I was on a Stanton Nuclear Security Fellowship at the Council on Foreign Relations in Washington, DC. For this opportunity, I am grateful to the Stanton Foundation; the Council on Foreign Relations; the Council’s senior leadership, including Richard Haass and James Lindsay; CFR senior fellows Michael Levi and Micah Zenko; and the individuals behind the Council’s fellowship programs, Janine Hill and Victoria Alekhine.
I benefited from feedback at a number of seminars where I presented earlier versions of this research. I thank participants at events at the American Political Science Association’s 2009 Annual Meeting; The Center for Strategic and International Studies; Georgetown University; The George Washington University; Harvard University; the International Studies Association’s 2013 Annual Meeting; Lawrence Livermore National Laboratory; Los Alamos National Laboratory; Michigan State University; Princeton University; the University of California’s Institute on Global Conflict and Cooperation; the University of California at Los Angeles; Wilton Park; US Strategic Command; US Office of the Secretary of Defense; US National Security Council Staff; US Navy submarine bases in Bangor, Washington, and King’s Bay, Georgia; Vanderbilt University; and Yale University.
For helpful comments on drafts of various parts of this book, I thank Victor Asal, Kyle Beardsley, Richard Betts, Philipp Bleek, Giacomo Chiozza, Jennifer Erikson, M. Steven Fish, Matthew Fuhrmann, Christopher Gelpi, Bruce Goodwin, Rebecca Davis Gibbons, Peter Henne, Robert Jervis, Paul Kapur, Michael Levi, Adam Mount, Abraham Newman, Robert Powell, Daryl Press, Marc Trachtenberg, Bob Vince, and two anonymous reviewers. My apologies to anyone I forgot.
I am indebted to William Hallisey, Anastasia Kazteridis, Miriam Krieger, Rebecca Kuang, Anthony Perisco, Sami Scheetz, Dane Shikman, Shannon Callahan Souma, Alexander Sullivan, and Michael Weintraub for helpful research assistance.
This book contains selections of material that have been previously published in other outlets, including International Organization, Journal of Peace Research, Foreign Policy, and Survival. I thank the editors of these outlets for the permission to draw on this material in the book manuscript.1
David McBride and his team at Oxford University Press did an outstanding job in helping me bring this book to press. I congratulate James Goldgeier, Bruce Jentleson, and Steve Weber on their editorship of the new Bridging the Gap Series. It is an honor to be among the first books included in what I believe could become one of the most exciting and important series in our field.
There are many individuals who have contributed to my development as a political scientist and a scholar. I could not have asked for a better friend or a more dynamic research collaborator on nuclear issues than Erik Gartzke. Giacomo Chiozza, Steve Fish, Michael Nacht, and Steve Weber, as you promised at my dissertation defense, you have remained my most trusted academic advisors throughout my career.
As always, thanks to my wonderful friends and family, including our newest addition, my beautiful daughter Eleanora. Finally, I am blessed to have married my best friend. Olivia, you make me happy, but more importantly, you make me a better person. This book is dedicated to you.
ABBREVIATIONS AND ACRONYMS
ALCM Air-launched cruise missile
C4ISR Command, control, communications, computers, intelligence, surveillance, and reconnaissance
CFR Council on Foreign Relations
CPO Causal process observation
CIA Central Intelligence Agency (United States)
DEFCON Defense condition (United States)
EMP Electromagnetic pulse
GAO Government Accountability Office
GDP Gross domestic product
H-PAC Hazard prediction and assessment capability
HEU Highly enriched uranium
IAEA International Atomic Energy Agency
IAEA AP International Atomic Energy Agency Additional Protocol
IAEA BOG International Atomic Energy Agency Board of Governors
ICB International Crisis Behavior Dataset
ICBM Intercontinental ballistic missile
ISR Intelligence, surveillance, and reconnaissance
JCPOA Joint Comprehensive Plan of Action (the Iran nuclear deal)
JPOA Joint Plan of Action (the interim Iran nuclear deal)
KT Kiloton
LOC Line of control
LRSO Long-range standoff weapon
MRBM Medium-range ballistic missile
MAD Mutually assured destruction
MCT Militarized compellent threat
MIRV Multiple independently targetable reentry vehicle
MT Megaton
NATO North Atlantic Treaty Organization
NPT Treaty on the Nonproliferation of Nuclear Weapons
NSG Nuclear Suppliers Group
PLA People’s Liberation Army (China)
PNE Peaceful nuclear explosion
PNI Presidential Nuclear Initiative
GLCM Ground-launched cruise missile
SAC Strategic Air Command
SLBM Submarine-launched ballistic missile
SLCM Submarine-launched cruise missile
SRBM Short-range ballistic missile
SSBN Subsurface ballistic nuclear (submarine)
T-LAM Tomahawk land-attack missile
UELE Use ’em or lose ’em
UN United Nations
UNSC United Nations Security Council
Introduction
Nuclear weapons have returned to the center of politics among nations. For half a century during the Cold War, nuclear forces were fundamental to the bipolar, strategic competition between the United States and the Soviet Union, but they temporarily receded into the background in the post–Cold War period. For the quarter century between 1989 and 2014, many viewed nuclear weapons as nothing more than Cold War relics. By 2009, serious people even debated whether complete nuclear abolition was within reach.1 It is now becoming clear, however, that this sustained de-emphasis on nuclear weapons was not achieved because humanity had somehow become more enlightened.
Rather, nuclear weapons remain the ultimate instrument of military force and they are still, therefore, essential tools of great power political competition. Such great power rivalries were muted when the United States emerged as the world’s unipolar power at the end of the Cold War and Washington overawed any potential peer competitors. The adversaries it did face in the 1990s and 2000s, such as Serbia, Afghanistan, Iraq, and Al Qaeda, did not possess nuclear weapons and the US nuclear arsenal was not directly relevant to the asymmetric security challenges these enemies posed.
But great power political competition has returned, and with it, the salience of nuclear weapons in world politics. In 2014, Russian President Vladimir Putin invaded Ukraine and, in the following year, intervened in Syria. In a bid to deter NATO intervention, Putin has made explicit nuclear threats and has brandished nuclear weapons at a level we have not seen since the end of the Cold War.2 China has become more aggressive in East Asia, claiming contested territory from US allies through military coercion. In the event of great power war in East Asia, there is a real risk of nuclear use. 3 Kim Jong Un in North Korea continues to conduct nuclear and missile tests and engage in nuclear brinkmanship against the United States. Moreover, these countries and others are taking steps to ensure they have the nuclear capabilities to support their nuclear strategies. In recent years, Russia, China, India, Pakistan, and North Korea have all expanded and/or modernized their
arsenals. Indeed, Yale political scientist Paul Bracken has argued that we are entering a “second nuclear age.”4
These developments demonstrate that nuclear weapons (despite the fond hopes of many) will likely remain an important feature of international politics for years to come. They also raise an important and enduring question with renewed relevance: what kind of nuclear strategy and posture does the United States need to protect itself and its allies in this new nuclear age?
According to a widespread and long-standing academic conventional wisdom, the answer to this question is straightforward: the United States needs a secure, second-strike capability.5 In other words, it must maintain a nuclear force capable of absorbing an enemy nuclear attack and retaining enough of a surviving force to retaliate with a devastating nuclear counterattack. So long as the United States (or any other nation) retains such an assured retaliation capability, scholars argue, no sane leader would intentionally launch a nuclear attack against it, and nuclear deterrence will hold.
These arguments are logical and persuasive, but, when compared to the evidentiary record, they point to an important puzzle. Empirically, we see that the United States has consistently maintained a nuclear posture that is much more robust than a mere second-strike capability. It possesses thousands of nuclear warheads, counterforce targeting policies and capabilities, missile defenses, and has more generally shown a recurring interest in military nuclear advantages over rivals.6 For example, during the Cold War, officials in Washington feared possible bomber and missile gaps with the Soviet Union and, in 1963, US President John F. Kennedy vowed to build a nuclear arsenal “second to none.”7 Even after the Soviet Union achieved numerical parity with the United States in the mid-to-late 1970s, Washington continued to search for military nuclear advantages with its “countervailing” strategy.8 And, at present, US officials and experts on both side of the aisle argue that the United States must retain a clear numerical superiority over China.9 As then–Secretary of State Hillary Clinton put it in 2010, “we’ll be, you know, stronger than anybody in the world as we always have been with more nuclear weapons than are needed many times over.”10 And, in 2016, US President Donald Trump said, “If countries are going to have nukes, we’re going to be at the top of the pack.”11
How do we make sense of this contradiction? Scholars argue that nuclear capabilities above and beyond a second-strike capability do not matter, but policymakers often behave as if they do. Leading academic deterrence theorists have noted the gap between theory and policy and have consistently concluded that the explanation is simple: policymakers are wrong. Perhaps most notably, Robert Jervis penned a foundational book on this subject titled The Illogic of American Nuclear Strategy. 12
Social science aims to explain the world around us, but existing theories do not help us understand empirical patterns of US nuclear strategy.
This book takes a different approach. Rather than dismiss it as illogical, this book explains the logic of American nuclear strategy. It argues that military nuclear advantages above and beyond a secure, second-strike capability can contribute to a state’s national security goals. This is primarily because a robust nuclear force reduces a state’s expected cost of nuclear war, increasing its resolve in high-stakes crises, providing it with coercive bargaining leverage, and enhancing nuclear deterrence.
This book defines a robust nuclear posture as a nuclear force larger and more sophisticated than a secure, second-strike capability, with capabilities designed to limit damage in the event of nuclear war. Nuclear superiority is defined as a military nuclear advantage over an opponent and it is operationalized according to a state’s expected cost of nuclear war. Nuclear superiority is a situation in which a state’s expected cost of nuclear war is lower than that of its adversary (even if the expected cost is high for both sides). As we will see later in this book, a state’s relative vulnerability to nuclear war is closely linked to the balance of nuclear capabilities between states, and “nuclear superiority” will, therefore, be used interchangeably with the terms “favorable nuclear balance of power” and, following past scholarship, “military nuclear advantages.”13
The argument of this book draws on well-developed bodies of scholarship on nuclear strategy and nuclear deterrence theory and brings them together to form a new synthesis. In so doing, it provides a novel theoretical explanation for why military nuclear advantages can result in international political advantages. From nuclear brinkmanship theory, this explanation draws on the idea that even if sane leaders are unwilling to intentionally launch a nuclear war, they have time and again shown themselves quite willing to risk one. Deterred from engaging in direct combat, nuclear powers attempt to coerce opponents by playing games of brinkmanship.14 They initiate or escalate crises, intentionally raising the risk of nuclear war in an attempt to force less resolute adversaries to capitulate. According to nuclear brinkmanship theory, therefore, the nuclear revolution transformed international politics from a competition in military capabilities to a “competition in risk taking.”15
From the nuclear strategy literature, this explanation borrows the insight that the nuclear balance of power affects nuclear war outcomes.16 Of course, the primary goal of nuclear strategy should be to prevent nuclear war. But if, God forbid, a war were to occur, analysts have argued that the United States should seek to limit the damage to itself and its allies to the greatest extent possible and a robust nuclear posture contributes to its ability to do so.17
The central theoretical argument of this book, which I label the superioritybrinkmanship synthesis theory, brings these strands of scholarship together to argue, quite simply, that military nuclear advantages increase a state’s willingness to run risks in international conflicts. A robust nuclear posture reduces a state’s
expected cost of war, increasing its resolve in international political disputes, and thus providing it with a coercive advantage over states more vulnerable to a nuclear exchange. When political conflicts of interest emerge, nuclear inferior opponents are less likely to initiate a military challenge and more likely to back down if the crisis escalates.
In more colloquial terms, the logic of the argument is simple: in a game of chicken we might expect the smaller car to swerve first even if a crash would be disastrous for both.
The idea that nuclear superiority is useful because it allows states to run greater risks in games of nuclear chicken might sound dangerous, but scholars and practitioners have long accepted that brinkmanship in high-stakes crises is an inevitable feature of the nuclear era. As Stanley Hoffman writes, the nuclear age is characterized by “the substitution of crises for wars.”18 In the words of former US Secretary of State John Foster Dulles, “The ability to get to the verge without getting into the war is the necessary art. . . . If you try to run away from it, if you are scared to go to the brink, you are lost.”19 Robert Jervis also recognized that “states are under especially great, and especially contradictory, pressures. War must be avoided, but . . . the other side’s need to avoid war can be used for leverage.”20
This logic of nuclear competition is universal, but there is good reason why the United States, arguably more than any other nation, has shown a strong and recurring interest in the maintenance of a robust nuclear force. Washington, unlike other nuclear powers, does not merely attempt to deter attacks against its homeland. Rather, it also extends nuclear deterrence to over thirty formal treaty allies in Europe and Asia. This “nuclear umbrella” protects the twenty-eight other members of NATO, Japan, South Korea, Australia, and arguably others. These nuclear security guarantees can be conceptualized as promises to play games of nuclear brinkmanship in the event of a crisis on behalf of noncontiguous and geographically distant allies against formidable nuclear-armed foes. The United States has a strong interest in protecting its allies and ensuring geopolitical stability in Europe and Asia. Nevertheless, in these contests, the balance of stakes generally favors US opponents. After all, Russia arguably has a greater interest in eastern Europe and China more of a stake in East Asia than does the United States. Since Washington starts from an endemic disadvantage in the balance of stakes, it seeks to make up for it with a favorable balance of military power. To credibly extend deterrence, in other words, the United States compensates for its stakes deficit with a capabilities surfeit.
This book addresses not only the benefits of a robust nuclear posture but also its costs. Critics of US nuclear strategy have argued that the pursuit of a robust nuclear arsenal is not only pointless but also risky, futile, dangerous, and costly. They have claimed that pursuing a lasting nuclear advantage is risky
because imbalances in power can lead to first-strike incentives and an increased chance of nuclear war;21 futile because adversaries will react quickly to close any gaps, resulting in unnecessary arms races;22 dangerous because it will encourage other nations to develop nuclear weapons, undermining international nonproliferation efforts;23 and financially costly, draining the national budget.24 These criticisms, however, point to a contradiction similar to the one posited earlier. Presumably, Washington would not have pursued and maintained these enduring elements of its nuclear strategy for decades if the downsides were truly so severe.
The second part of the book, therefore, explores the alleged disadvantages of nuclear advantages. The book finds that there are, indeed, costs to the maintenance of a robust nuclear force, but that they are less steep than many claim. Turning first to strategic stability, it shows that theoretical logic and available empirical evidence suggest that nuclear superiority, not nuclear parity, contributes to more, not less, strategic stability. Next, to examine nuclear arms races, the book presents a new theoretical argument about the origins of “underkill.” It explains why states are often unable or unwilling to match the nuclear capabilities of competitors and demonstrates that, empirically, nuclear arms races are uncommon and the United States has often achieved lasting nuclear advantages. This is followed by a study on the relationship between US nuclear weapons and nonproliferation. This study shows that there is not an observable link between a large US nuclear arsenal and the proliferation and nonproliferation policies of other states. Finally, an examination of the US nuclear budget explains that a robust nuclear force is indeed costly, but also affordable. If one believes, therefore, as then–US Secretary of Defense Ashton Carter argued in 2016, that nuclear weapons are the “bedrock of our security,” and the “most important mission of the Department of Defense,” then it is also a good value.25
This book attempts to explain the logic of American nuclear strategy, but this is not to suggest that the details of US nuclear strategy are unchanging or not subject to debate. To the contrary, features of US strategy have been altered over the years in response to new strategic environments and changing presidential administrations.26 In addition, there have always been, and will likely continue to be, heated political and analytical fights about many aspects of US nuclear policy.27 But, at the same time, there have been enduring elements of US nuclear posture, namely, the maintenance of nuclear force above and beyond a secure, second-strike capability, that existing scholarly theories simply cannot explain. This book attempts to articulate the underlying rationale for building and maintaining such a force.
Neither does this book provide an in-depth description of contemporary US nuclear policy. Readers interested in those matters can consult the congressionally mandated Nuclear Posture Review and the Nuclear Employment Strategy
published by each US presidential administration.28 Rather, this book gets at the deeper, strategic motivations for why US politicians, policymakers, operators, and warfighters have often shown an interest in maintaining a robust nuclear force and a favorable nuclear balance over potential adversaries.
While academics often engage in either/or debates, the argument of this book argues for a both/and understanding of nuclear dynamics. It maintains that nuclear superiority matters, but it also finds support for many traditional arguments in the field, including those advanced by Jervis and others.29 I concur that a minimum nuclear force is likely sufficient to deter a deliberate enemy nuclear attack. Indeed, that is one of the central theoretical premises on which the argument of the book is based. After all, there are zero data points to suggest otherwise. If, however, one is interested in going beyond the question of deterring intentional nuclear attack to exploring other elements of nuclear diplomacy, then a broader understanding is needed. Nuclear weapons contribute to other national security objectives (or in the words of social scientists, dependent variables), including nuclear war outcomes, coercive bargaining, and deterrence of lower-level challenges, and to understand these issues, one must take into account the nuclear balance of power. Existing scholarship is not entirely incorrect, therefore. It is merely incomplete.
Similarly, this book also finds support for the idea that political stakes matter for crisis bargaining among nuclear-armed nations. Existing scholarship acknowledged that nuclear-armed states would often find themselves in high- stakes games of nuclear brinkmanship, but they argued that the nuclear balance of power was irrelevant to these contests.30 Rather, they maintained that a state’s resolve in these disputes depends on the issues at stake in the crisis. States fighting for national survival, for example, would be willing to run a greater risk and, therefore, be more likely to prevail, than states concerned with political influence in a distant geographic region. This book finds quite a bit of support for these arguments. But it also finds that the nuclear balance of power matters too.
Arguments that conventional military power shapes international crisis bargaining also find some support, but not to the exclusion of nuclear strength. To be sure, these factors are often correlated, but the book seizes on all available opportunities to tease them apart. The evidence suggests that both matter, but perhaps unsurprisingly, the nuclear balance of power tends to be more salient than the conventional balance in conflicts among nuclear-armed states.
Other alternative explanations for international crisis bargaining find less support. Recently scholars have argued that nuclear weapons are irrelevant due to a growing normative “nuclear taboo,” or that their importance has been exaggerated as a result of “nuclear alarmism,” but these arguments do not stand up in the face of the evidence.31 The book demonstrates that nuclear
weapons have featured prominently in great power competition from 1945 to the present.
Another more subtle variation of this argument holds that nuclear weapons matter for deterrence (threats to defend the status quo) but not compellence (threats aimed at changing the status quo). Nuclear compellence skeptics argue that nuclear weapons do not affect compellent threats because it is difficult to credibly threaten nuclear attack and because states cannot use nuclear weapons to take and occupy territory.32 On these specific points they are correct, but they largely overlook other important mechanisms by which nuclear weapons influence international bargaining. As this book argues, leaders cannot credibly threaten to launch a suicidal nuclear war, but they can credibly threaten to risk one and the nuclear balance of power influences these contests in risk taking. Nuclear compellence skeptics consider the possibility of brinkmanship, but then they define it so narrowly as to render it virtually meaningless. Moreover, as we will see, the evidence presented in this book is much more supportive of the superiority-brinkmanship synthesis theory than of the nuclear compellence skeptics.
In a recent book, Vipin Narang analyzes the nuclear postures of regional nuclear powers.33 This is groundbreaking work, but as Narang explicitly argues and as this book will show, his study of regional nuclear powers is often not relevant to understanding superpower nuclear postures or American nuclear strategy.
Recently, scholars have also debated whether democratic states enjoy an advantage in international crisis bargaining because they are better able to credibly signal their intent through the generation of “audience costs.”34 This book does not find much support for the idea that democratic states perform better than their autocratic counterparts in conflicts among nuclear powers. Future research can explore whether this is because nuclear crises operate according to a different logic, or perhaps because there is merit to the growing chorus of criticism against the democratic advantage hypothesis.35
Some might argue that the maintenance of a robust US nuclear force is driven by bureaucratic politics and the military services’ parochial interests in garnering resources and prestige by being involved in the nuclear mission. These factors played some role in developing certain capabilities in the early days of the Cold War (such as the Navy’s development of nuclear-armed submarines), but this explanation cannot account for why the United States has continued to sustain a robust nuclear force for decades. As we will see in chapter 7, the services have grown less enthusiastic about the nuclear mission over time, which they see as a diversion from their core organizational identities, and they have often been forced by civilian leadership to maintain and upgrade nuclear capabilities. Moreover, even proponents of bureaucratic politics explanations of arms races
acknowledge that these factors only amplify and channel arming dynamics, but are generally insufficient on their own to produce a national decision to build up forces.36
In sum, the superiority-brinkmanship synthesis theory provides a better explanation for competition among nuclear powers than do rival theories.
This book contains several important implications for the academic study of nuclear deterrence theory and for policymakers responsible for formulating nuclear strategy. For decades, scholars have argued that advantages in the nuclear balance of power above and beyond a secure, second-strike capability do not matter. For example, in addition to the Illogic of American Nuclear Strategy, Jervis authored an article titled “Why Nuclear Superiority Does Not Matter.”37 David Alan Rosenberg examined the origins of what he termed America’s unnecessary nuclear “overkill” capability.38 As Glenn Snyder and Paul Diesing write in their classic study of nuclear deterrence, “There is the puzzling question of whether simple quantitative nuclear superiority does confer some bargaining advantage. . . . Pure logic gives a clear negative to this question.”39 They continue, “Perversely, the real world does not quite follow this logic. Many policy makers do seem to believe that simple ‘superiority’ somehow confers a crisis bargaining advantage. The belief may be explained in some cases as merely a lack of sophistication about nuclear strategic theory.”40 In other words, unable to make sense of empirical phenomena using their theories, scholars, such as Snyder and Diesing, did not discard their theories, but discounted the empirical evidence. This response is perhaps understandable, but the job of social scientists is to explain the world as it is, not to reject it as nonsensical.
For decades, however, a clear explanation for this behavior has not been forthcoming. Charles Glaser maintained that “the logical case” for the argument that nuclear superiority matters for international politics “is weak, proponents have done little to support their claims, and efforts to fill in the logical gaps in their arguments encounter overwhelming difficulties.”41 Barry Blechman and Robert Powell agree, writing, “If there is such a case, it has yet to be made.”42
In contrast to previous scholarship, this book provides a novel theoretical explanation for why nuclear superiority matters even if both sides possess a secure, second-strike capability. In so doing, it helps to resolve what may be the longest-standing, intractable, and important puzzle in the scholarly study of nuclear strategy.
This book makes empirical as well as theoretical advances. Earlier generations of scholars were handicapped by a relative lack of data. As Jervis acknowledged at the time of his writing, “our knowledge of nuclear deterrence . . . is largely deductive. We have a number of plausible theories, but only very limited empirical evidence.”43 Over thirty years have passed, however, since he wrote these words, providing the current generation of scholars with decades of additional
data and developments in social science methodology to apply to these longstanding questions. Recent years have seen an explosion of rigorous social science research on nuclear weapons issues.44 Inference is improved with more data, so it is unsurprising that this book finds relationships and patterns among variables that were not yet evident when foundational studies were conducted decades ago.
This book also makes a methodological advance by modeling a technique useful for those interested in “bridging the gap” between scholarly international relations theory and foreign policymaking.45 Scholars tend to design studies that examine the relationship between a single independent variable and a solitary dependent variable. But policymakers must wrestle with how a single independent variable (or in their conceptualization, a policy choice) might affect an entire range of dependent variables (i.e., national security interests). This book does not, therefore, stop after examining how nuclear posture relates to deterrence, but continues to consider how it affects other interests important to policymakers, including warfighting, stability, arms races, nuclear nonproliferation, and the national budget.
Perhaps most importantly, this book has implications for US nuclear policy. Indeed, it articulates a logic of American nuclear strategy. The book’s central argument would suggest that, all else being equal, the United States (and other states in competitive security environments) should seek to maintain strategic superiority over any potential rival. But all else is rarely equal. Policymaking involves the setting of priorities and making difficult trade-offs among many desirable, but often conflicting, policy goals. Reasonable people, therefore, can and often do disagree about nuclear policy in particular and national security policy more broadly. The findings in this book cannot instruct policymakers about what their priorities should be, but good social science can more modestly inform them about what trade-offs they may face. Correctly understanding the effects of choices in strategic nuclear policy matters not simply for academic analysts of nuclear deterrence, therefore, but also for those who are charged with deterring nuclear conflict in the future.
Plan of the Book
This book is divided into two parts and nine chapters. The first part considers the advantages of nuclear superiority. The following chapter, chapter 1, presents the central argument of the book. It uses a game theoretic model and verbal argumentation to explain the superiority-brinkmanship synthesis theory. It demonstrates how a nuclear advantage increases a state’s effective resolve and improves its bargaining leverage in international disputes. The chapter also develops
