In recent years, numerous Western-born Muslim men (and a few women) have been seduced by militant Islam and have died for its varied causes thousands of miles from home. In this volume, Wiktorowicz departs from the ever-expanding scholarship on terrorism that seeks to explain its origins, its structural and historical underpinnings, or its objectives and motives. Instead, this author seeks to explain why Muslims in the West are drawn to radical groups and how they are convinced to engage in what the author calls “high-risk, high-cost activism.”

To do so, he applies the theoretical lens of social movement theory to his case study of the London-based al-Mujahiroun, led by Omar Bakri Mohammad. (Bakri has not been allowed back into the United Kingdom since August 2005.) Al-Mujahiroun's core tenet, before being disbanded by October 2004, was “the use of military coups to establish Islamic states wherever there are Muslims, including Britain” (p. 7). It was not easy being an al-Mujahiroun activist: members were expected to attend a “dizzying array of required weekly activities” and to center their lives on the movement. This often meant sacrificing “work, friends, family, and leisure time” (p. 47). Activists had to pay dues and donate one third of their salary to the organization. Given organizational time commitments, activists took jobs that paid less but allowed them to participate in group activities. Some activists lost their jobs over their affiliation (p. 51). Members were often jailed and fined for violating ordinances and laws pertaining to public order and were targeted by antiterrorism measures. Members were often marginalized by mainstream Muslims who derided them as the “lunatic fringe” (pp. 54–76). Al-Mujahiroun activism was costly and risky. Despite these disincentives to affiliate, the group attracted 160 “formal members” and another 700 followers who took lessons from Bakri and other authorized instructors throughout the United Kingdom.

To understand how this group attracted recruits and to understand the decision-making process of those recruits, the author conducted “unfettered interviews with activists” during trips to the United Kingdom between June and December 2002—notably with Bakri's explicit permission. The author studied hundreds of movement documents and attended numerous group activities, including propagation tables, demonstrations, religious lessons, and outreach programs, as well as movement-only study lessons. In an effort to have some semblance of a control group of nonjoiners, he commissioned a small survey of London-based Muslims. In total, 104 persons provided information: seventy-three submitted paper surveys (of 350 distributed), and another thirty-one persons completed a Web version of the same. (The author himself notes that this is only a convenience sample and thereby limits the generalizability of the findings. He nonetheless defends this exercise, noting the near impossibility of obtaining a statistically representative sample.)

Drawing upon this rich empirical base, the book poses and answers three interrelated questions.

• First, it asks what explains recruits' initial interest in such groups. The author argues (in chapter 2) that individuals begin a path of “seeking” that is precipitated by a “cognitive opening that shakes certitude in previously accepted beliefs” (pp. 5, 85–128). This allows potential activists to be vulnerable and receptive to new ways of thinking. Cognitive openings can include experiences with discrimination, socioeconomic crisis, and political repression, or they can be catalyzed through group activism and outreach.
• Second, the book asks how an individual, once exposed to a particular group, is persuaded that the organization is a legitimate and credible source of Islamic interpretation. Wiktorowicz takes the expanse of the third chapter (pp. 135–65) to explore how Omar Bakri Mohammad maintains his sacred authority to interpret Islam and thus confers to the group its corporal legitimacy.
• Third, the volume asks how individuals are persuaded to engage in “high-risk” activism. The author argues that socialization is important here. Al-Mujahiroun, through its expansive program of education and activities, “tries to shift individual understandings of self-interest in a manner that facilitates progression to risky activism. Potential participants are taught that salvation is an individuals' primary self-interest” (pp. 7, 167–200).

Wiktorowicz makes a compelling case explaining the process by which individuals join al-Mujahiroun. The author also makes laudable attempts to explain why some Muslims who experience “cognitive openings” do not turn to al-Mujahiroun, even upon exposure to the group. Whereas the author acknowledges that the issue of nonjoiners is an empirical gap in his work, his small survey of Muslims allows him limited insights. Specifically, he finds that one of the most important differences between joiners and nonjoiners is that the latter had a firm grounding in their Muslim faith and identity before their cognitive opening. The former did not. Wiktorowicz also sought out defectors, because they comprise another kind of control group. Wiktorowicz's interviews with defectors suggest that some left because their sense of Bakri's legitimacy diminished. Others left in the wake of 9/11, when the social and legal risks expanded. From these interviews, the author proffers three observations. First, cognitive openings are recurrent events and can catalyze defections when the group's ideology cannot resolve new issues. Second, group consistency matters: when the leaders appear to betray the cause, members may become disillusioned and defect. Third, risks and costs can change over time and alter the self-interests and priorities of the member (pp. 196–99).

One of the strengths of this volume is that it offers potential insights into non-Muslim groups as well. However, one of its major deficiencies is that it is ultimately a descriptive analysis. Wiktorowicz's subject comprises one of the most pressing contemporary public-policy problems in Western democracies. Yet, the author provides little discussion of the immense policy implications of his work in the conclusion or elsewhere. This is unfortunate because the author likely has much to contribute here. Despite this shortcoming, this study should be of interest to a wide array of academic scholars and students in the fields of political science, sociology, and policy and security studies. Policymakers and nongovernmental policy analysts will also benefit from this volume, despite its neglect of policy implications.