This volume comprises some of the key essays by Professor Crenshaw, from 1972 to the present-day, on the causes, processes and consequences of terrorism. Since the early 1970s, scholars and practitioners have tried to explain terrorism and to assess the effectiveness of government responses to the threat. From its beginnings in a small handful of analytical studies, the research field has expanded to thousands of entries, with an enormous spike following the 9/11 attacks. The field of terrorism studies is now impressive in terms of quantity, scope, and variety. Professor Crenshaw had studied terrorism since the late 1960s, well before it was topical, and this selection of her work represents the development of her thought over time in four areas: defining terrorism and identifying its causes the different methods used to explain terrorism, including strategic, organisational and psychological approaches how campaigns of terrorism end how governments can effectively contribute to the ending of terrorism. This collection of essays by one of the pioneering thinkers in the field of terrorism studies will be essential reading for all students of political violence and terrorism, security studies and IR/politics in general.