In the 21st century, more than any other time, US agencies have relied on contractors to conduct core intelligence functions. This book charts the swell of intelligence outsourcing in the context of American political culture and considers what this means for the relationship between the state, its national security apparatus and accountability within a liberal democracy. Through analysis of a series of case studies, recently declassified documents and exclusive interviews with national security experts in the public and private sectors, the book provides an in-depth and illuminating appraisal of the evolving accountability regime for intelligence contractors.