Combating Jihadism: American Hegemony and Interstate Cooperation in the War on Terrorism. By Barak Mendelsohn, Chicago, IL: University of Chicago Press, 2009. 304 pp., $45.00 paperback (ISBN-13: 978-0-226-52011-7). Barak Mendelsohn breathes new life into English School theory and policy relevance with Combating Jihadism: American Hegemony and Interstate Cooperation . As a state-centric perspective focusing on the rules and order of “international society,” the English School (ES) has been a realist cousin, whereby state interests and power matter but with a hint of sociality defining legitimate action in ways that transcend realist materialism. Just what exactly ES offers in contrast to realism and other theoretical views has not always been clear in the thirty-plus years since Hedley Bull's foundational book, The Anarchical Society . Mendelsohn revisits the perspective, freshens it up with policy-relevant focus on both the transnational terrorism and the age of American hegemony. In so doing, he relates these two as twin forces that international society guards against in its pursuit of survival and stability as a community of sovereign states. While not wholly successful in his theoretical or empirical tasks, he makes a plausible case for taking norms and normative behavior seriously in the study of both counterterrorism and hegemonic orders. Mendelsohn's thesis is that transnational “jihadism” is a threat to international society. He argues that disparate states with their own interests nonetheless come together and cooperate because of a desire to preserve the social order threatened by transnational jihadists. Such various states set aside differences and bear high material costs to do so, even following the “hegemonic” power, the United States, to uphold the survival and stability of international society. But, cooperation is contingent on the hegemon's leadership being …