When the Stakes Are High: Deterrence and Conflict Among Major Powers.

By Vesna Danilovic. Ann Arbor: University of Michigan Press, 2002. 312p. $55.00.

Deterrence Now.

By Patrick M. Morgan. New York: Cambridge University Press, 2003. 358p. $70.00 cloth, $25.00 paper.

Deterrence is a theory that incorporates psychological, economic, political, and military ideas about the prevention of war through the threat of disproportionate punishment to would-be challengers of a given status quo. This notion was built into military and diplomatic measures that defined national security policymaking for millennia. Yet the convergence of deterrence theory and the policy peaked during the nuclear era. This theory appealed to both academic scholars and to policymakers as a middle-of-the road alternative to appeasement or Armageddon.

Research on deterrence over the past two decades required reconsideration of many of the traditional maxims of deterrence theory. Quite a few studies tested the fundamental propositions of the theory. In addition, the political developments of the last two decades—the end of the Cold War, the rise of wars of low-intensity conflict, and the challenge of international terrorism—raised new issues about the theory and practice of deterrence. The two studies reviewed herein reflect these trends.

Vesna Danilovic's book sets out to test several propositions about the conditions for the success and failure of deterrence. Danilovic argues that deterrence theory failed to distinguish between threats that are inherently credible and those that are not. Not all threats are inherently credible in the sense that the deterrer has a fundamental interest in the issues at stake. In some cases, the deterrer may have a general interest in maintaining an image of resolve and commitment even when the issues at stake do not serve immediate interests. She contends that the more intrinsically important the issues at stake, the more credible the deterrent threat, and thus the more likely is deterrence to work. She points out that other factors—in particular, capabilities, resolve, and reputation for honoring commitments—are at work as well. Danilovic's contribution lies in the assessment of the effect of inherent credibility on the stability of deterrence.

The second chapter of When the Stakes Are High consists of an elaborate discussion of major powers and global contenders. This discussion does not do justice to the subject because it is clearly not immediately related to the question of deterrence as it may well take place in situations involving or excluding major powers. Dealing with major powers only may well generate biased inferences. The theoretical rationale for the population of cases analyzed in this book is better served by Appendix B (pp. 225–30), which provides an operational definition of major powers and major power contenders.

Danilovic distinguishes between general and immediate deterrence and between direct and extended deterrence (Patrick M. Morgan, Deterrence: A Conceptual Analysis, 1983). She views immediate deterrence as failed general deterrence (pp. 54–56). The study focuses on all four types of deterrence, as opposed to other studies that typically focused on cases of immediate-extended deterrence. (A notable exception is Paul Huth and Bruce Russett [“General Deterrence Between Enduring Rivals: Testing Three Competing Models,” American Political Science Review 87 (March 1993): 61–73], who tested general deterrence, in addition to previous tests of extended deterrence.)

This study offers a set of carefully constructed empirical tests of the impact of two sets of variables on deterrence outcomes. The first set—capabilities and resolve—is derived from traditional deterrence theory. The second set of factors—intrinsic credibility and regime-related domestic costs—has received less attention in the literature.

The findings suggest that all four factors affect the onset of a deterrence effort and deterrence success. The ratio of the defender to a challenger's capabilities, the defender's relative regional interests (the measure of inherent credibility), the defender's past behavior (a measure of resolve), and the defender's democracy score increase the likelihood that deterrence would be applied in conflict, and the probability that the deterrence effort would be successful (the challenger acquiesces, or a compromise is reached).

One problem with the study is its failure to encompass a fundamental distinction between conventional and nuclear settings with regard to what constitutes high stakes. Beyond the intrinsic interests of the defender and challenger, the stakes are also defined by the type of deterrence and the capabilities involved. The United States attempted to overcome the credibility gap in Europe during the Cold War by placing tactical and intermediate nuclear weapons on the Soviet Union's doorstep. A distinction between nuclear and conventional deterrence is equally or more significant to the definition of stakes than are trade- or alliance-related indicators of inherent credibility. It would have been profitable to examine the robustness of the findings with respect to nuclear and nonnuclear episodes of deterrence.

This criticism notwithstanding, Danilovic's work is a significant contribution to the literature on deterrence. The author combines hypotheses from traditional deterrence theory with original hypotheses concerning the effect of inherent credibility on deterrence, and she lays out a careful design for examining these hypotheses. The findings offer ample food for thought for the application of deterrence in a post–Cold War world. The book should be studied by students and practitioners of deterrence, and it carries significant implications for the practice of deterrence in a unipolar world.

Deterrence Now is an ambitious undertaking by a scholar who has made significant conceptual contributions to the study of deterrence in the past. Patrick Morgan attempts to assess the state of knowledge on deterrence theory and policy to date. In addition, he also addresses several new challenges to deterrence theory and policy, some of which did not receive sufficient attention in the literature, and some of which are an outgrowth of the post–Cold War world.

The first chapter discusses the practice of deterrence during the Cold War era. The discussion leads to a somewhat mixed conclusion: “[Nuclear weapons] were not irrelevant, but their main contribution lay in heightening incentives for war avoidance, … promoting caution in a very severe political conflict, and avoiding the appeal of cheap-victory strategies which nuclear weapons themselves made possible” (p. 41).

The second chapter discusses rationality and deterrence. It reaches a controversial conclusion that rationality is not necessary for deterrence. Moreover, the irrationality of deterrers may account for deterrence success in some cases. None of these arguments is supported by facts. Rather, Morgan's argument is that the debate between rational deterrence theorists and their critics could be resolved by removing rationality as a requirement of deterrence altogether. Quite a few scholars from both the rational deterrence school and its critics would have some problems with this argument.

Morgan's review of the empirical literature suggests that there exists a remarkable convergence across empirical studies of deterrence, regardless of genre and method. Nuclear weapons per se do not have a dominant effect on deterrence outcomes. The overall record of deterrence efforts is mixed, with some positive results. The challenger's motivation is the most important factor determining deterrence success or failure. Finally, local rather than overall military balances affect deterrence outcomes.

The last part of the book consists of an analysis of collective actor deterrence, the effect of the Revolution in Military Affairs (RMA) on deterrence, and the future of deterrence in a post–Cold War world. Morgan freely admits (p. 201) that much of the discussion is speculative due to the lack of empirical research on these subjects. However, his insights are worthy of serious consideration. He argues that collective actor deterrence is likely to be tenuous and difficult to manage. Clearly, the failure of collective action deterrence in the case of Iraq—a process that unfolded after the book had been in press—supports this observation.

Morgan's assessment of the effects of RMA on deterrence is more optimistic. Technology is seen to have a positive impact on the ability to deter through the use of surgical strikes and “post-heroic” warfare (Edward N. Luttwak, Strategy: The Logic of War and Peace, 2001, pp. 68–80). At the same time, other factors, such as the proliferation of weapons of mass destruction and information warfare, may offset these positive implications.

Deterrence Now is an exceptionally well written book. It is impossible to escape the specialized jargon of deterrence discourse. Morgan, however, does a superb job of explaining the key concepts and the fundamental practical dilemmas of deterrence. The clear language makes this book a pleasure to read, both for the uninitiated and for those versed in the deterrence literature.

The book addresses important issues that received only rudimentary treatment in the past, and reconsiders deterrence in light of recent technological and political changes. On both matters, the discussion is sensible and illuminating. Some of the insights are bound to be controversial, however. The argument about deterrence without rationality is controversial and may even be self-defeating. The discussion of the inherent difficulties in testing deterrence theory is questionable. This seems to be contradicted by Morgan's comprehensive review of the numerous large-n and case study–based studies, which suggests that not only is such testing possible, but it also yields fairly consistent cross-method and cross-study findings. Finally, his lumping together of compellence (or compellance, as spelled in the book) and deterrence might raise considerable objection. These are fundamentally two different—and, in my view, diametrically opposed—issues. Deterrence is, as Morgan argues correctly, a theory of war avoidance through the use of threats. Compellence is a theory of the use of force for political purposes that may entail both dissuasion and coercion. As Clausewitz's classical definition of war goes: “War is an act of force designed to compel our enemy to fulfill our will” (Carl Von Clausewitz, On War, 1973 [1832], p. 1). This strange wedding of the two concepts raises quite a few questions about the assessment of collective actor deterrence or of the effects of RMA on deterrence.

This said, however, this book is an important contribution to the study of deterrence. It should become essential reading to anyone who wishes to understand how deterrence was practiced in the past and what kind of challenges the theory and the practice of deterrence face down the post–Cold War road that lies ahead.