How Terrorism Ends: Understanding the Decline and Demise of Terrorist Campaigns. By Audrey Kurth Cronin. Princeton: Princeton University Press, 2009. 330p. $29.95. Combating Jihadism: American Hegemony and Interstate Cooperation in the War on Terrorism. By Barak Mendelsohn. Chicago: University of Chicago Press, 2009. 304p. $45.00. doi:10.1017/S1537592710002914 — Ivan Arreguín-Toft, Boston University Both Audrey Kurth-Cronin and Barak Mendelsohn have written books that should be read. The two books approach the subject of terrorism from remarkably different angles, and each is most successful as a source of background information to crucial policy questions but least success- ful in providing guidance related to those questions. Both are polemical—each author has an axe to grind with pre- vious research or policies—and perhaps because of this, in terms of policy guidance or implications, each makes its strongest contribution in negative form: as in “here is what has been missed,” or “here is what has been misguided” about previous efforts to understand terrorism in its trans- national contexts. Mendelsohn’s central argument is that Hedley Bull’s “English School” of international relations theory— which, in brief, imagines a society of self-interested states whose cooperative behavior cannot be reduced to the inter- ests of any single state (or to coalitions of states)—is a useful lens through which to understand both the degree and quality of interstate cooperation in response to the threat of radical Islamic terrorism. Combating Jihadism is organized into two parts, containing a total of nine chap- ters. The first part of the book (Chapters 2–4) focuses on the nature of the threat to “international society,” and the second (Chapters 5–9) focuses on the nature of the inter- national response to that threat. The strength of the book lies in its insistence on the importance of nonmaterial factors—including shared norms and identities—in explaining interstate relations. The book also shines in its summary and review of both the English School’s contribution to our collective under- standing of international politics and such largely (and equally?) moribund theoretical traditions as hegemonic stability theory. Finally, Mendelsohn usefully reminds us that Al Qaeda’s ideology is, in fact, far more ambitious in its scope than is captured by the majority of its public pronouncements about “Western influence” and troop deployments. Three weaknesses of Mendelsohn’s analysis work to undermine its strengths, however. First, the book is not designed as a contest between competing explanations. So, we wonder right away about the value added of the English School’s approach as compared with simpler expla- nations. If we assume that states act in their own interests first, and later describe those self-interested acts as “ben- efiting all states” or “civilization,” then why could inter- state cooperation not emerge and take place without the need for the elaborate intellectual superstructure of an imagined international society? The author argues not only that serious interstate cooperation is unusual but also that states intentionally act to defend international society. The difficulty is that there is no evidence adduced to support either claim, and in the absence of that support, it seems just as plausible to assert that the defense of this imagined society is a beneficial, yet unintended, consequence of the pursuit of narrow self-interest in the same way that a mar- ket is the beneficial, yet unintended, consequence of com- petition between modestly regulated and self-interested firms. So, it is not clear what we gain by using the lens of the English School to explain interstate cooperation in the years following September 11, 2001 (other than its reha- bilitation as a going international relations perspective). Second, Mendelsohn must demonstrate not only that Al Qaeda seeks the violent destruction of international society but also that its desire to do so is sufficiently threatening to activate and sustain societal agency. The argument takes the form of domino logic, in which a well-supported claim that Al Qaeda seeks to acquire and use weapons of mass destruction (WMDs) is conflated with the assumption that it will inevitably be successful in getting hold of and using them. Using WMDs is then necessarily assumed to constitute a threat to inter- national society. But setting aside the question of whether Al Qaeda will acquire WMDs, why should we assume that WMDs would prove sufficient to destroy any partic- ular state, or the state’s system as such? Moreover, the author’s own evidence supports an alternative explana- tion: The structure of the threat determines the structure of the response; so a transnational threat is, in most ways, best countered by a multilateral effort. His analysis reminds us that on threats that simply cannot be countered uni- laterally (such as terror operations funding via global finan- cial transactions), there is a great deal of interstate cooperation. It is simply not clear why this is surprising, nor why it might demand an English School perspective in order to appreciate. Third, Mendelsohn runs into difficulties trying to rem- edy the gap between what the English School might pre- dict by way of cooperation and U.S. unilateralism (particularly under the leadership of George W. Bush). In one of the book’s stronger contributions, the author takes this threat to the English School head-on, showing that, in fact, the United States acted in ways that were constrained by its (social, not material) peers. Hege- mony, Mendelsohn usefully reminds us, is about leader- ship, not necessarily belligerent domination. But the effort highlights a more serious problem: What if the society Bull conceived of as international is really Western soci- ety, and, by extension, the chief threat to Mendelsohn’s attempt to reintroduce an English School utility is not December 2010 | Vol. 8/No. 4 1273