Want to know how the geopolitical world works these days? Then forget the analytical frameworks and abstract models, says Peter J. Katzenstein, the W.S. Carpenter Jr. Professor of International Studies at Cornell University.

"Think of the world as regions organized by America's imperium," writes Katzenstein in the preface to his latest book, "A World of Regions: Asia and Europe in the American Imperium" (Cornell University Press, 2005).

Observing the dramatic shift in world politics since the end of the Cold War, Katzenstein cogently argues that regions have become critical to contemporary world politics. This view is in stark contrast to those who focus on the purportedly stubborn persistence of the nation-state or the inevitable march of globalization. In detailed studies of technology and foreign investment, domestic and international security, and cultural diplomacy and popular culture, Katzenstein examines the changing regional dynamics of Europe and Asia, which are linked to the United States through Germany and Japan.

Regions, Katzenstein contends, are interacting closely with an American imperium that combines territorial and nonterritorial powers. He argues that globalization and internationalization create open or porous regions. Regions may provide solutions to the contradictions between states and markets, security and insecurity, nationalism and cosmopolitanism. Embedded in the American imperium, regions are now central to world politics.

Katzenstein specializes in security policy and political economics; the relationship between international and domestic politics; Germany in Europe; and Japan in Asia.

His many books include "Cultural Norms and National Security: Police and Military in Postwar Japan," "Small States in World Markets: Industrial Policy in Europe," "Corporatism and Change: Austria, Switzerland and the Politics of Industry," "Network Power: Japan and Asia" and "Tamed Power: Germany in Europe."