In his seminal 1958 paper The Delicate Balance of Terror, political scientist Albert Wohlstetter famously argued that nuclear deterrence was far less intrinsically stable than was commonly supposed. Rather, he contended that the decisions necessary to uphold deterrence “are hard, involve sacrifice, are affected by great uncertainties, concern matters in which much is alto- gether unknown and much else must be hedged by secrecy; and, above all, they entail a new image of ourselves in a world of persistent danger. It is by no means certain that we shall meet the test.”
Consciously echoing Wohlstetter’s sober conclusions, Vipin Narang and Scott Sagan provide an update in their collected volume, The Fragile Balance of Terror: Deterrence in the New Nuclear Age. The book underscores that however successful (or lucky) practitioners of deterrence have been thus far, the contemporary strategic landscape presents unique challenges, many without Cold War-era precedent, that demand new ways of thinking about deterrence. Narang and Sagan are eminently qualified to edit this volume.
Narang is currently the Acting Assistant Secretary of Defense for Space Policy, overseeing nuclear policy, and previously served as the Frank Stanton Professor of Nuclear Security and Political Science at the Massachusetts Institute of Technology. Sagan serves as co-director and senior fellow in the Center for International Security and Cooperation at Stanford University and has been a leading light in nuclear proliferation studies for decades. The 11 additional experts who contribute to this book likewise represent a wide variety of academic perspectives broadly centered on deterrence, lending substantial credibility to the volume.
The Fragile Balance of Terror is divided into two halves. Part I, “New Challenges in the New Nuclear Age,” examines those characteristics of the 21st century strategic landscape that render the contemporary character of deterrence fundamentally distinct from its Cold War–era precursor. Caitlin Talmadge begins by analyzing the multipolarity of contemporary deterrence, arguing persuasively that although the presence of more nuclear-armed states may provide a marginal positive contribution to strategic stability, it will simultaneously present more avenues for miscalculation. Rose McDermott examines the regime types that typify new and emerging nuclear weapons states, concluding that leaders of personalistic regimes (for example, North Korea) may be easily provoked and less easily deterred. Narang and Heather Williams subsequently examine the influence of social media on deterrence dynamics, concluding that a platform’s intended audience, whether it is “open” or “closed,” and the duration of a crisis constitute independent variables in measuring this influence. Finally, Amy Zegart JFQ 115, 4th Quarter 2024 questions whether the rise of open-source intelligence is an unalloyed good in the nuclear sphere, contending that the con- temporary information landscape in fact raises the stakes that incorrect or misleading information might drive an ill-advised decision or that the difficulty of concealing one’s actions might foreclose the ability to save face, incentivizing riskier courses of action.
Part II, “Enduring Challenges With a New Twist,” analyzes those aspects of deterrence that present contemporary policymakers with new challenges but do not signal fundamental shifts in deterrence itself. Jeffrey Lewis and Ankit Panda begin by examining how states define nuclear “sufficiency,” concluding that such definitions are more dynamic than static and are more closely tied to political objectives than to technological or operational thresholds. In a particularly well-argued chapter, Christopher Clary reevaluates claims that technological advances in areas such as targeting and remote sensing have rendered nuclear forces less survivable against counterforce attacks. He concludes that strategic instability is a less likely outcome of such advances than is muted security competition, or “arms jogging.” Giles David Arceneaux and Peter Feaver thereafter consider how regional powers’ nuclear command and control systems reflect their nuclear strategies, demonstrating that such powers delegate or retain authority to employ nuclear weapons according to their own unique strategic environments, nuclear strategies, and domestic political circumstances, rather than following in the path of their Cold War forebears. Concluding part II, Mark Bell and Nicholas Miller refute the optimistic argument that “nuclear learning” naturally induces nuclear-weapons states to moderate their security policies in the quest for strategic stability, aptly demonstrating that such a hypothesis is supported neither by theory nor by the historical record.
One of The Fragile Balance of Terror’s greatest strengths is that the arguments presented draw on the full range of deterrence’s global history, especially its contemporary history. Williams and Narang, for example, consider social media’s influence over the Indo-Pakistani skirmishes in 2019 as well as on deterrence dynamics between the United States and North Korea during the Trump administration. These examples respectively illustrate that today’s regional nuclear powers may respond differently to domestic constituencies than the United States and the Soviet Union once did and that even nation-states with deep expertise in deterrence remain vulnerable to strategic missteps. Other case studies demonstrate simultaneous continuity and discontinuity with historical precedent. For example, Zegart recounts the improbable virality of a 2011 student exercise by a former Pentagon official whose misjudged allegations of a massive Chinese underground stockpile of nuclear weapons provoked consternation within the Pentagon and Congress. This episode underscores that while intelligence remains as essential as ever in evaluating the capabilities and intent of nuclear-weapons states, nation-states no longer wield a monopoly over sensitive intelligence and have far less control over its public influence. The consistency with which contributors to The Fragile Balance of Terror ground their arguments in broad historical research, including by reference to case studies not commonly featured in published research, capably reinforces the book’s central thesis that the stability of deterrence cannot be taken for granted.
One shortcoming, if a modest one, is that the authors gloss over the potentially destabilizing effects of advanced delivery systems and their enabling technologies. Hypersonic glide vehicles, fractional orbital bombardment systems, and more peculiar weapons, such as Russia’s “Poseidon” unmanned underwater vehicle, may well present challenges to deterrence in the not-too-distant future. With this being the case, their omission here seems a missed opportunity, given other chapters’ focus on such diverse technologies as commercial satellites and social media. Readers seeking a primer on such delivery systems and their consequences for deterrence will not find it here. Still, they will nonetheless find this book highly informative regarding the less apparent factors complicating deterrence.
The Fragile of Balance of Terror is a compelling contribution to the study of nuclear deterrence. It further complements other recent scholarship, notably Keir Lieber and Daryl Press’s The Myth of the Nuclear Revolution (Cornell University Press, 2020), in reevaluating many of the assumptions underpinning modern conceptions of deterrence. The complexity of the contributors’ arguments renders The Fragile Balance of Terror best suited for those in academic, military, and policymaking circles with a grounding in the history and theory of deterrence. Yet one of the book’s underlying themes—that the mere possession of nuclear weapons remains insufficient to deter an adversary—notably runs contrary to popular perception. As the United States embarks on a costly and controversial whole-of-triad modernization, those who view recapitalization as essential to national security would do well to draw on the lessons of this book in educating the public about the necessity and difficulty of upholding deterrence. As Albert Wohlstetter first observed more than 60 years ago, deterrence remains far too fragile to be taken for granted. JFQ