I highly recommend Douglas Lemke's book to all scholars and students who study international conflict and war. This study is an extension of work conducted by the author since the early 1990s, some of which was published in the major quantitatively oriented journals in the field of international politics. The book integrates and advances the theoretical arguments and empirical findings of those earlier studies and makes a notable contribution in the area of peace and conflict analysis. I believe that although it is of primary interest to scholars, it may prove useful in advanced undergraduate classes on international relations and in graduate-level courses on international conflict.

Lemke proposes revisions to standard power transition theory and extends that thesis to an explanation of minor power wars. He hypothesizes that within both global and local power hierarchies, preponderance in capabilities by a dominant state decreases the likelihood of war. If a dissatisfied challenger achieves power parity with the dominant state (in either global or local hierarchies), the probability of war is postulated to increase. Hence, this “multiple hierarchy” model moves power transition theory into the context of regional interactions. The book also contains an excellent review of traditional scholarly works that touch on the subject of multiple hierarchies (e.g., Hans Morgenthau, Martin Wight, Edward Gulick, and Hedley Bull, among others).

The book opens with an interesting and insightful discussion of the differences between generalist and area studies and then applies the distinction to the study of war. The author correctly notes the prevailing tendency of generalists to apply theories designed to explain only major power behavior to minor power dyads and to do so without consideration of possible regional differences. The potential costs of this research strategy are clearly drawn.

In Chapter 2, Lemke presents an excellent discussion and clarification of the “timing problem” of war occurrence in power transition theory, plausibly explaining why unstable capability balances at any point around general parity between satisfied and dissatisfied states should be associated with the onset of war. Chapter 4 describes his technique for delineating international regions. I consider this aspect of his work to be a major achievement. His identification of “local hierarchies” in terms of the ability to interact militarily is both novel and important. The statistical analyses in Chapters 5 and 6 are performed expertly and explained so carefully that even readers with little or no statistical background will be able to follow and understand the analysis.

One of the more interesting aspects of the book involves an examination of an apparent “African Peace” that the author identifies in his analysis. Here, he explores a variety of possible explanations that would discount the finding, rejecting them one by one, until he is satisfied that the statistical evidence is substantive. He concludes by offering a credible rationale for the cross-regional variation in his results.

I have only a few quibbles with the study: First, Lemke's discussion of the “prevention problem” in Chapter 2 ignores several empirical studies dealing with power balances and the initiation of preventive wars by status quo defenders. The findings of these studies are relevant to this component of power transition theory and are supportive of the basic thesis. Second, the discussion of the South Asia local hierarchy in Chapter 4 is a bit truncated. Specifically, the absence of China in this hierarchy requires an explanation. Not only do Indian/Chinese military plans and weapons procurement policies consider future conflict, but the dyad also engaged in war in 1962. Third, I am not convinced of the validity of “extraordinary military buildups” as an indicator of dissatisfaction with the status quo (Chapter 4, pp. 104–9). However, Lemke goes to great lengths to explain his choice, and readers will have to reach their own conclusions about the validity of the measure.

My final quibble concerns the discussion (in Chapter 8, pp. 202–4) of “rebel states” acting “as though they were great powers,” which is given as an explanation for major power/minor power wars that produce greater-than-average battle deaths. This account might have benefited from an observation that major power involvement in regional politics frequently pits the major power against a dominant regional state. In other words, it is not necessarily the minor power “acting as though it were a Great Power” that stimulates conflict, but rather major power intervention in distant areas that provokes violence with a local power at or near the apex of a regional hierarchy. Such an observation would not be inconsistent with the theoretical foundation of the multiple hierarchy model.

Again, these are merely quibbles. Lemke's Regions of War and Peace is an excellent work that not only broadens and enhances the research program of power transition theory, but also raises important questions about the impact of multiple hierarchies and regional variation in the study of international politics. It is a major achievement by an accomplished young scholar.