A chilling global investigation into how modern surveillance states are built and why they endure--from a journalist once spied upon in Cold War Europe. How much freedom must we surrender to feel safe? Is China's all-round AI-enhanced surveillance becoming a model for other countries? Could cascading fears about failing states and welfare systems steer citizens towards accepting repressive measures, even in well-established democracies? The Watchersis a timely, indispensable account of the modern police state. Establishing its historical antecedents, Roger Boyes shows how it became an instrument of control under the Nazis and in the Eastern Bloc--and is still central to the governance of Iran, North Korea, China and Russia today. Is America now adopting police-state methods to facilitate the mass deportation of migrants? What are the limits to political control over the judiciary? And what is happening to democratic guardrails worldwide? Boyes speaks with the police state's victims and insiders: to former inmates of Iran's Evin Prison, to Hongkongers fighting for democracy, and to those who chronicled the vicious abuses of Syria's torture factories. He also tracks down the people who informed on him when he was a correspondent in East Germany and in martial-law Poland. Understanding the motives of willing accomplices, he argues, is as important as outlining the secrets of the new caste of securocrats and their seemingly unstoppable rise.