Although deterrence was a popular subject with a large and vibrant literature for decades, many scholars switched to other topics following the Cold War. However, the renewed threat of major interstate conflict in recent years has brought a resurgent wave of attention to the subject. Recent works by scholars such as Matthew Fuhrmann, Keir Lieber and Daryl Press, and Frank Zagare have breathed new life into the study of deterrence.

Erik Gartzke and Jon R. Lindsay build on this knowledge base in their book Elements of Deterrence: Strategy, Technology, and Complexity in Global Politics. Unlike many works on the subject, Gartzke and Lindsay go beyond just focusing on nuclear deterrence, or even on the difference between nuclear and conventional deterrence. Modern US national security policy focuses on integrated deterrence across a wide range of dimensions, and Gartzke and Lindsay engage with this multifaceted approach by examining land, sea, air, space, and cyber dimensions, as well as gray zone conflict and even international trade.

Satisfyingly, the book focuses on general deterrence, which relates to seeking to maintain the status quo, rather than immediate deterrence that seeks to prevent crises from escalating. Both are certainly important, but while immediate deterrence success enables states to avoid war, successful general deterrence prevents crises from occurring in the first place. An exception is their model of gray zone conflict, which assumes that the challenger and defender are in a crisis, and thus general deterrence has already failed. While preventing gray zone conflict from escalating to war is important, deterring gray zone challenges from arising in the first place seems to be harder.

Gartzke and Lindsay develop a new theory of deterrence that is grounded in the bargaining model of war. They relate each of the four key parameters of the bargaining model with a different aspect of deterrence: demand with coercion, which they call warning; power with defense, or winning; cost with deception, or watching, and uncertainty with accommodation, or working. This allows them to assess the comparative advantages of different approaches to securing policy objectives. The book is ambitious with many strengths and is part of an impressive broader research program. However, there are a few important issues to consider.

Gartzke and Lindsay contrast their theory with classical deterrence theory, which represented the conventional wisdom during the Cold War. Unfortunately, they do not account for perfect deterrence theory, a key alternative. While they cite works by Zagare and others associated with perfect deterrence theory, Gartzke and Lindsay simply lump them together with classical deterrence theory rather than accounting for the distinctions between them. The two theories differ centrally in their treatment of credibility. Classical deterrence theory assumes that states always prefer to back down yet tries to determine how states can make threats credible despite their irrationality. Perfect deterrence theory recognizes that threats can only be credible if they are rational to carry out. Fortunately, Gartzke and Lindsay are closer to the latter view, examining how using various means sends different signals regarding preferences.

In their chapter on land warfare, Gartzke and Lindsay focus on the impact that military deployments have on extended deterrence. They argue that the presence of deployed forces within the protégé’s territory increases credibility, while offshore deployments undermine credibility and therefore lessen deterrence stability. Their argument that the presence of military forces sends a stronger signal of extended deterrent threat credibility than deployments nearby but not within the protégé’s territory certainly makes sense. But while presence and offshore deployments are important alternatives to consider, there is another that is ignored: not deploying forces at all. By arguing that offshore deployments lessen credibility, the implication is that states should leave forces at home if they are not willing or able to deploy them within the protégé’s territory. For example, they argue that keeping Marines forward deployed to Okinawa sends a more credible signal than pulling them back to Guam. But what about the difference between forces deployed to Guam in comparison to keeping forces at home? Similarly, do US and other NATO forces in Germany contribute to the deterrence of a Russian attack on the Baltic countries, or do only troops physically located in, say, Latvia, contribute to deterring Russian attacks on Latvia? I certainly agree that in-country deployments contribute to deterrence, but it seems questionable to argue that nearby forces do not.

While Gartzke and Lindsay report empirical results that support their expectations, there are unanswered questions about their analyses because the reader is often referred to other works for complete details about them. For example, their empirical results regarding extended deterrence are focused on the deterrence failure rate, but they do not specify how that is measured. They report failure rates for offshore balancing over 60%, which seems very high, particularly for cases of general deterrence. However, since the measurement of variables is left unspecified, it is not possible to assess the validity of the empirical results reported in the book without relying on other published or unpublished sources.

The chapter on naval power also raises questions. Gartzke and Lindsay’s central argument is that major naval powers will engage in more MIDs, suggesting that they are less able to deter challenges. However, it seems that major naval powers attempt deterrence more often, particularly since the leading naval powers in the past two centuries have been Britain and the United States, who have also been the leading states in the system. Perhaps looking at a deterrence failure rate would be appropriate here.

Gartzke and Lindsay move on to examine the impact of specific types of naval platforms on deterrence. They find that battleships greatly increase the probability of MIDs, aircraft carriers decrease them, and submarines have a small positive impact. They argue that this variation is about uncertainty, but I find the focus on battleships odd for a couple of reasons. First, while they find that “battleships make disputes more likely, without increasing diplomatic recognition or augmenting the projection of power” (p. 247), it is not clear if this was also true when battleships, rather than aircraft carriers, were the capital ships. A key reason that aircraft carriers are beneficial for diplomatic recognition and power projection is that they are the capital ships, the role that battleships used to play. Second, focusing on battleships is not particularly relevant to thinking about modern or future deterrence since no countries have possessed battleships in decades or are likely to in the future.

I was impressed to see that Gartzke and Lindsay included a chapter on trade because while policymakers talk about a whole of government approach to deterrence, academic research often examines only the military—or even just nuclear—aspects. However, that also makes their decision earlier in the book to focus on defense, coercion, and deception to the exclusion of accommodation even more puzzling. Early in the book, they “omit accommodation here as we are focusing on military means” (p. 85), while later they examine trade to “focus on non-military instruments of power” (p. 303). It would have been nice to see the military and non-military aspects of deterrence compared together.

Gartzke and Lindsay make a strong contribution to our understanding of deterrence with this excellent book. Their effort to use the bargaining model of war to explain deterrence is novel and deserves further attention. Their analysis of the differential impact of land, sea, air, space, cyber, and other dimensions on deterrence should pave the way for subsequent research to further examine deterrence across a broad range of categories. That would also help to bridge gaps between deterrence and other aspects of international security.