The role of the police has, from its beginnings, been ambiguous, even janus-faced. This volume focuses on one of its controversial aspects by showing how the police have been utilized in the past by regimes in Europe, the USA and the British Empire to check political dissent and social unrest. Ideologies such as anti-Communism emerge as significant influences in both democracies and dictatorships. And by shedding new light on policing continuities in twentieth-century Germany and Italy, as well as Interpol, this volume questions the compatibility of democratic government and political policing.