The Paramilitary Turn examines how American law enforcement became a central actor in national security during the twentieth century, reshaping the boundaries between civilian and military power. Tracing the rise of paramilitary policing from the Progressive Era through the Cold War reveals how police institutions and the professionals who led them adopted military structures, tactics, and strategic thinking, while maintaining their civilian identity. This transformation created a security apparatus that operated through familiar civic institutions rather than direct military rule. Drawing on archival records from police departments, federal agencies, intelligence organizations, and international police programs, Ryan T. Reynolds describes how policymakers relied on civilian police forces to manage unrest, gather intelligence, advise foreign governments, and project American influence abroad. These efforts linked domestic policing to overseas internal security and counterinsurgency campaigns, integrating law enforcement into the broader national security apparatus. Police agencies and the experts who led them became part of a broad network that included private foundations, universities, municipal departments, state and federal agencies, and organizations like the International Association of Chiefs of Police. By placing police within the analytical framework of military history, The Paramilitary Turn bridges operational history with war and society, reframes civil-military relations, and broadens the study of grand strategy to include law enforcement. Further, it challenges the assumption that coercive power in a democracy flows only through the armed forces, arguing that the foundations of a distinctly American form of a garrison state emerged through civilian institutions that performed military functions.
