Anyone older than 40 working in the field of international security studies will have a well-developed attitude to yet another talk, paper, or discussion of deterrence. Those younger than that are more likely to be confused by or uninterested in the fuss. The Cold War is gone, and so is the bipolar world so amenable to the deterrence literature everyone reads (or at least used to read) in graduate school. It is hard to care how one defines deterrence if one views it as a strategic option whose day is past and whose pursuit is idealistic at best, resource draining at worst. The language used here is deliberately provocative to make the point that a strong deterrence skeptic (for cybered conflict) such as myself was surprised and informed by this book.

In their edited volume, Erik Gartzke and John Lindsay assemble 15 discussions addressing “cross-domain deterrence” to see if this iteration of the more traditional concept is a fit for today’s world. The book contains excellent and compact summaries of the deterrence concept’s logical and empirical evolution, married to the researchable question whether cross-domain deterrence (CDD) can iterate deterrence into usefulness again. A different title might have been “Deterrence: What Needs to Be Researched Today for It to Work Again.” One could design multiple research programs or dissertation proposals on the questions raised in the first half of the book alone.

Given that the edited book is about laying out logic, empirical examples, and questions, each chapter is an exploration, not a solution, and is less a proffered argument than an opening salvo for which future work is much needed. The authors largely tie CDD to their topic, and the coeditors integrate the discussions at the beginning and the end with observations on CDD’s paradoxes, complex systems surprises, whole-of-society threats, and rising uncertainty about defense traditions in implicitly consolidated democracies.

In exploring whether CDD helps update a dated, era-specific topic, the first handful of chapters constitute a particularly nice tour de force summarizing the intellectual, historical, and logical conundrums of applying deterrence theory to today’s major challenges. In their respective chapters, Patrick Morgan, Jacqueline Schneider, Ron Lehman, and the coauthors Michael Nacht, Patricia Schuster, and Eva Ulribe concisely lay out the challenges, historical baggage, and the uncertainties of dragging deterrence into the current and increasingly post-western era. If one had only two slots in the syllabus for articles on deterrence updated for the coming post-western era, any two of these would do very well to inform students about what lay behind and to stimulate discussion of what lies ahead.

In their well-crafted introduction and conclusion, the coeditors incorporate complexity and the ambiguities of changing means, circumstances, or political interests into the discussion of what the “cross-domain” aspect of CDD reflects. Might CDD be a way to name and therefore adapt to the unavoidable uncertainties that the coming international system redefinition will pose to westernized states? In that vein, inclusion of the Chin-Hao Huang and David Kang chapter outlining the more complacent, less militarized approach to the rise of China pursued by most of its regional neighbors is excellent. If cross-domain deterrence would be hard, then in today’s coming world, CDD strategies that require the involvement of friendly non-allied Asian states that do not see a Chinese military threat are likely to be very challenging indeed.

Having said that, several chapters might be better suited for a different collection of essays. Historical explanations or orthogonal conceptual attacks on a topic are always desirable. Of course, one can easily understand how the authors would have endorsed trying CDD out as a reinterpretation of history, as an unacknowledged conceptual child of particular strains of political science, or in unusual applications such as coercive migration. Accordingly, various chapters approach CDD from the history of satellites, strategic bombing, and Athens versus Sparta, as well as international law, linkage politics, and mass human movement as deliberate deterrence. However, some of these chapters were less persuasive as good fits for the volume’s mandate. The chapter on international humanitarian law, for example, presents an argument well known in the modern security studies debate (especially in discussions of cyber norms), but did not exceptionally advance the CDD case. The linkage politics chapter argued for a theoretical approach to CDD that would situate the newly reborn deterrence concept in a known niche in political science. Unfortunately, it is more of a scholarly argument for the modern relevance of “linkage politics” than a test of CDD, and it also belongs elsewhere.

The historical case studies have mixed results with respect to the persuasiveness of their reinterpretation of events to meet the CDD proof test. The chapter on coerced migration is a case in point. The topic would have intrigued me, but the execution was stretched. Taken to extreme, any mass movement of fleeing people can be interpreted as a deliberate act of CDD against the receiving state—or it could just be state leadership eliminating unwanted subpopulations, regardless of where they go, and hence is not CDD. To a lesser extent, the otherwise fine piece on Athens and Sparta by Joshua Rovner suffers a similar problem of fit. The endless conflict between the two states could indeed be a paradoxical and orthogonal outcome of mismatched efforts to coerce across different domains. But it could also be a rather common fact of history that does not make the case for CDD all that directly. When riverine nations feud with mountaintop fiefdoms, neither chooses to fight on the other’s preferred terrain or the intruder is likely to die, making it more self- than cross-domain deterrence. Topics requiring a stretch to link to the modern notions of CDD dilute the message of the volume. On the other hand, their inclusion could also be the Machiavellian hand of the coeditors making the case—again—about how much more needs to be done. If CDD is truly a viable adaptation of the old deterrence concept for the new, more uncertain, and complex global system, history is not going to easily give up indicators of what cross-domain deterrence is or can do, where, and by whom.

Overall, this volume is a definite contribution to the literature that should find itself on scholars’ bookshelves and graduate-course syllabi. It predictably concludes with a call to action for scholars to take up the theoretical challenges of cross-domain deterrence, and it is particularly well crafted. For the confusion, surprises, and inevitable setbacks facing defenders of democracies in the coming era, it is especially necessary to establish whether CDD can make deterrence again into a useful and productive strategic option. If CDD can help defend consolidated democracies and some remnant of their international regime from a world racing madly out of their control by helping adapt dated defense strategies, ideas, and thinking, then work needs to start now on the questions raised by this volume.

All the ideas expressed in this review are solely those of the author and do not reflect the positions of any element of the US government.