This book is concerned with Western militant Salafism. It is not alone. Terrorism, and particularly this form, is currently the subject du jour in a discipline where few phenomena capture the public imagination for a sustained period. Spurred particularly by the 2001 attacks on the United States, heightened by further killings in Madrid, London and Amsterdam, and fuelled by frequent stories of numerous other threats planned or prevented, militant Salafism has become one of the most prominent and controversial issues in contemporary politics. Yet despite, or perhaps because of, the significance attached to this topic, disagreements continue to rage over such matters as the role of religion, political grievances, levels of social integration and the extent and nature of the threat posed by this form of terrorism. Indeed, even the foremost analysts in the field cannot agree on the most basic elements of militant Salafism and the threat it offers. As The New York Times recently noted, a bitter

For his part, Marc Sageman claims that militant Salafism is now devoid of an overarching, hierarchical structure.