This book explores the international politics behind the identification of human trafficking as a major global problem. Since 2000, tackling human trafficking has spawned new legal, security and political architecture. This book is grounded in the premise that the intense response to this issue is at odds with the shaky statistics and contentious definitions underpinning it. Given the disparity between architecture and evidence, Wylie asks why human trafficking has become widely understood as a threat to personal and state security in today's world. Relying on the idea of 'norm lifecycle' from constructivist International Relations, this volume traces the rise and impact of anti-trafficking activism. Global common knowledge about trafficking is now established, but at a cost. Taking issue with the predominant framing of trafficking as sexual exploitation, this book focuses on how contemporary globalization causes labour exploitation, while the concept of trafficking legitimates states' securitized responses to migration.