Stern, who has devoted years of study to her subject, strings together accounts of her many interviews with terrorists and former terrorists in a very readable book that treats mainly Muslims but gives careful attention to Christian and Jewish terrorists as well. The style is that of a personal odyssey, in search of the roots of religious militancy. She skips often from specific to general and from one country or religion to another, relating her own concerns and working hypotheses while weaving into the narrative many insights from studies in disciplines as diverse as psychology and history. The first part sets out five categories of grievances that move people to embrace terrorism (alienation, humiliation, demographics, history, and territory). The second treats the different patterns of terrorist organization; she considers charismatic leaders, lone-wolf avengers, and commanders and their cadres, as well as the "ultimate organization" that takes advantage of all of the above, al Qaeda being the classic example. After sifting the many different motives that impel people to terrorism and the different modalities of terrorists in action, she concludes with "policy recommendations" that amount to no quick fix but are sensible steps, appropriate to the harsh reality that she has so effectively illuminated.