Examining how British security politics evolved during the Northern Ireland 'Troubles' and situating this evolution within the long-term history of Anglo-Irish relations, Michael Livesey explores the emergence of the UK's first counter-terrorism laws and development of novel peacebuilding strategies leading to the Good Friday Agreement. Drawing on parliamentary debates from 1920 to 1972 and archival records from the Troubles era, Livesey reveals how these innovations were shaped by inherited patterns of political thought. Introducing a framework for understanding the historical origins of contemporary policies and processes, Livesey's account demonstrates how strategies for managing violence did not emerge in isolation but grew from a conceptual ecology inherited through past generations of discursive practice. This book offers a rich and historically informed perspective with far reaching insights into the origins of policies that continue to shape global counter-terrorism and peacebuilding today.