It is conventional wisdom these days that World War I, just to choose one historical example, was most likely the outcome of recklessness by political leaders, unstable alliances, and an arms race between Germany and Britain over the previous years. But emphasis on which factor to privilege as the most important varies depending on whether an actor-based or structural explanation of Great Power politics is favored. If many historians have often sided with the former, most international relations experts tend to prefer the latter. The purpose of Bear Braumoeller’s book is to offer a way out of this dilemma by proposing and empirically testing a systemic theory of Great Power politics that sees agency and structure as internally related to each other, rather than as the distinctive and separable perspectives that are usually presented. As the author writes (p. 18): “The signal insight to be gained from the book is an understanding of the process by which states simultaneously shape and are driven by the structure of the international system. In contrast to existing ‘top-down’ (structural) or ‘bottom-up’ (agentic) explanations . . . this one connects parsimonious models of the citizen, the state, and international structure to produce a coherent, dynamic, fully systemic model—one that, unlike the structural theories of decades past, possesses a coherent set of microfoundations at the individual and state level.”

This is an ambitious task. Previous efforts in this direction, as Braumoeller notes, foundered on their indeterminate character and failure to distinguish what they could explain (such as levels of state security–related activity) from what they could not (specific disputes, war outbreaks, alliances). The “nested politics” model he presents in Chapter 2 is the centerpiece of the book. This makes four straightforward claims. First, citizens’ worldviews lie behind the demands they make of their leaders in relation to the international system. Second, the state in turn conveys these preferences and interests to the leaders. Third, the capabilities of the state limit the ability of leaders to carry out what their constituencies desire. Fourth, and finally, the existing relations of states in the system as a whole affect the distribution of power and thus the translation of lower-level demands into higher-level outcomes. The author summarizes this approach as one in which state sovereignty is “nested within hierarchy nested within anarchy” (p. 16).

Subsequent chapters take up the evaluation of multiple empirical hypotheses that subject the theory to tests of both quantitative and qualitative (narrative) varieties. In Chapter 3, Braumoeller presents detailed statistical analysis of three international systems: the post–Napoleonic War European system, the period between the two world wars, and the Cold War. Besides showing convincingly that mainstream balance-of-power arguments do not work very well in accounting for security-related behavior within these periods, the empirical analysis suggests that political ideology (worldviews) is possibly the most important driver. The sort of structural realist arguments emphasizing discrete state “interests” that have increasingly informed constructivist and Marxist accounts as well as conventional neorealist ones are thus found wanting. The author places the details of the statistical analysis into two appendices that while available to those wishing to examine the nested-politics model, leave the flow of the text in the chapter undisturbed by the usual clutter of statistical discussion.

In Chapter 4, three subperiods of the longer systemic periods used in Chapter 3 are the subject of fairly detailed narratives. These are the interstate polarization of the period 1815–34, the end of U.S. isolationism in 1940, and the end of the Cold War between 1985 and 1990. Each makes a compelling case for its arguments, respectively, that British liberalization preceded a conservative reaction; that the U.S. government was already tilting against Germany in 1940, fully 18 months before the putative “sudden” involvement of the United States in World War II as a result of the Japanese navy’s attack on Pearl Harbor; and that it was a changing Soviet worldview, associated above all with the persona of Mikhail Gorbachev, that was the “trigger” for the end of the Cold War rather than anything else.

The book makes a strong case for its systemic perspective and against those theories that have long been dominant in international studies, particularly that of structural realism. The nested-politics model directly challenges the absurdity of separating domestic and foreign politics as if they were ever separable realms in practice. The distinction between latent and realized capacities of states again helps to undermine the lazy assumption, common particularly in recent rediscoveries of vulgar geopolitics, that simply because a state has a capacity it could use in a particular way, it must necessarily use it that way. The empirical analysis is based on a thorough grasp of historical details and the uses and limitations of periodization. When lacking in appropriate quantitative measures for some indicators, Braumoeller displays an imagination that is all too rare, for example, by using a survey of diplomatic historians to collect information about the worldview and state-activity variables that he uses in Chapter 3 to great effect. Each of the case studies in Chapter 4 is strong in its own right, but the example on the end of the Cold War is simply a tour de force. It is the single most convincing narrative on this topic that I have read.

My major criticism would be that The Great Powers and the International System probably dwells too long on the deficiencies of the currently dominant perspectives in international relations theory. But perhaps this is inevitable when you are laying out an alternative to them. Braumoeller is also probably unfair to Karl Marx when he associates him with the structural and Thomas Carlyle with the Great Men theories of history. Marx obviously thought that agency could intervene in history. Some of his disciples with their “gearbox” theories of history have once more gotten him into trouble. The focus on the worldviews of citizens is also all very well, but when political elites are not responsive to their populations, it is difficult to see how this influence can operate. Would simply identifying the worldviews of “competing domestic interests” and the politics of foreign policymaking that leads some of those to triumph at different times perhaps make more sense across more Great Powers? Finally, in moving beyond the tired polarities of much contemporary international relations theory, the author has had to constrain his empirical focus to Great Powers.

The next move in the intellectual liberation promised by Braumoeller’s systemic focus would be to extend the theoretical logic to nonstate actors and the small states that receive short shrift in the story told so far. That would be to abandon even more definitively the epistemological orthodoxy that is here cast convincingly into enormous theoretical and empirical doubt.