This book is about patterns of conflict and cooperation within major regions of the world. Why are some regions characterized by conflict, even war, while others are stable, peaceful and cooperative, even intensely so? Which factors are in play when regions change from one mode towards another? Western Europe, for example, has become a peaceful security community and Southeast Asia and the Southern Cone of Latin America have seen elements of security-community-building as well while the Middle East and South Asia remain mired in enduring rivalries.

Such a project requires precise concepts, an assortment of theories and an historical frame. This is provided by the first two chapters written by T.V. Paul (Ch. 1) and Barry Buzan (Ch. 2). Both present similar definitions of regions; here is Paul’s version: “a cluster of states that are proximate to each other and are interconnected in spatial, cultural and ideational terms in a significant and distinguishable manner” (p. 4). Paul’s chapter also introduces the major theoretical approaches to the study of regions: realism, liberalism, constructivism and eclectic perspectives. Buzan emphasizes the formative history of regions: they are connected to colonization and decolonization; they are homogenous in the sense that they are made up of sovereign states which is a political form imposed by the West. They are uneven because of some of these states are rather weak entities and some regions have deep historical roots while others do not. At the same time, they vary in patterns of amity and enmity. A more intensely globalized world will reduce the importance of regions, but Buzan is convinced that they will remain important “for some decades to come” (p. 44). The once dominant West appears set to be reduced to one or two regions “in a more decentered international system/society containing several regional cores” (p. 45).

The chapters that follow are organized according to theoretical approach. Realist perspectives get two chapters. Dale C. Copeland has his own preferred realist theory but he situates it instructively in a broader landscape which includes classical realism, hegemonic stability theory and neorealism. Systemic realist theory needs adaptation in order to be applied to regions, says Copeland, because regions are not in pure anarchy, there are influential great powers external to the region. His “Dynamic Differentials Theory” aims to show how power differentials interact with declining power trends; profound decline by leading states (or their rivals) can destabilize a system to the point of war. Jeffrey W. Taliaferro’s neoclassical realism, by contrast, focuses on the grand strategic choices of an extra-regional hegemon and the leading states within the region in order to explain transitions from zones of conflict to zones of relative stability.

Liberal perspectives get three chapters. John M. Owen, IV, generally defends the liberal claim that interdependence pacifies relations among states but he also emphasizes that regional interdependence does not emerge automatically. Stephanie C. Hofmann and Frédéric Mérand focus on formal international organizations; they point to a combination of institutional strength and flexibility which is peculiar to the successful security community in EU-Europe. Institutions in other regions are either less strong and/or less flexible. John R. Onealargues that democratization is the major force in creating peaceful regions, supported by economic interdependence and regional institutions. He also rejects the “clash” argument by Huntington and the Snyder and Mansfield claim that there is more conflict in democratizing states.

The constructivist approach is employed in two chapters. Amitav Acharya identifies three ways in which ideas influence regional orders: foundational ideas of individuals and societies can make up the basis of regional orders; further, processes of socialization and bargaining change and develop existing norms in new ways; and finally, there is an effect from the response to outside ideas in terms of mimicking and emulation. Vincent Pouliot argues that regions are constituted by practices—specific ways of doing things—which organize the security game. He demonstrates how the Russia-NATO relationship after the end of the Cold War is a game of “mismatched practices” where one side has not been able to convince the other that it really wants to move toward a new structure of more cooperative relations.

Finally, there are two chapters on eclectic perspectives. John A. Hall takes on the transformation of Europe from a zone of war to a zone of peace. He generally supports Norrin Ripsman’s view, according to which the European transition is related to “realist transition and liberal endurance”. That is to say, the United States provided a framework of security and stability setting the stage for European integration to take place and the liberal political and economic factors then made the process move forward. These conditions were unique to Europe and for that reason the European experience “gives few lessons to the rest of the world” (p. 254). Norrin Ripsman’s chapter stresses the importance of realist conditions for a successful process of peacemaking. Great power balancing, hegemonic influence and the motives of state leaders are the “top-down” factors that drive peacemaking, not the “bottom-up” factors of democratic institutions and norms, economic interdependence or cooperative identities.

The book is a fine achievement. It is particularly helpful in providing, on the one hand, a valuable conceptual and historical introduction to regions and, on the other hand, a comprehensive and precise application of realist, liberal and constructivist theory to the problems of regional change, conflict and peace. The chapters will be of great interest to all students of IR theory and regional transformation.

I have two reservations. One concerns the ambition set forth by Stéfanie von Hlatky in the conclusion: the book wants to “draw bridges between realism, liberalism, and constructivism rather than opting for a division-of-labor approach” (p. 297). But most of the book is based on a clear division of labor where authors present the relative merits of different realist, liberal and constructivist perspectives. Even the two chapters that are understood to be eclectic (Hall and Ripsman) strongly underline the importance of realist conditions for the peace processes that they analyze. The other concern is that the analytical perspective is predominantly from within specific regions. That downplays the question of what general role regions will play in a future world order but perhaps this is a topic for another volume.