"Kupchan's book is fascinating, thought provoking, and consequential."-- Henry Kissinger "Using historical studies of rapprochement, security community, and union as pillars for a stable world order in the twenty-first century, Charles Kupchan once again leapfrogs conventional foreign policy wisdom. He rightly foresees the elements of and a blueprint for a new global commons, one constructed of mutual interest. This is a mature work produced by a mature thinker."-- Gary Hart, former U.S. Senator "This is a work of admirable breadth and unusual interest. Combining an interesting theoretical framework with an extraordinarily diverse set of case studies, Kupchan has produced a lucid work that should be valued by both the academic and policymaking worlds in sorting out the relationships among classic diplomacy, democracy, and peace.

"-- Anthony Lake, Georgetown University "In this intellectual tour de force Charles Kupchan provides a theoretically ambitious, admirably eclectic, and empirically rich account of the different worlds of international relations that are normally studied in isolation: anarchy, rapprochement, security community, and union. Statecraft not regime attributes, and politics not economic interdependence, put enemies on the pathway to peace, starting with unilateral accommodation and ending with the generation of new narratives and identities. This is a big book in every sense of the word and a major scholarly achievement."-- Peter J. Katzenstein, Cornell University "Theoretically ambitious and historically audacious, How Enemies Become Friends is an invaluable and timely contribution to our understanding of the causes of war and peace. Grounded in international relations scholarship and informed by an intimate knowledge of the actual practice of international security, Kupchan's book deserves to be read by scholars and practitioners alike."-- Michael Barnett, University of Minnesota "This is an extremely ambitious book about a very important topic. It delivers through a well-crafted combination of theoretical innovation and detailed case studies.

Kupchan offers a powerful and carefully assembled argument that will have a substantial impact on the field of international relations."-- Daniel Deudney, Johns Hopkins University.