Throughout 1944 and 1945, ‘Wild Bill’ Donovan lobbied energetically for Presidents Roosevelt and Truman to act and establish the skeleton of a peacetime intelligence organisation. Truman gave him short shrift, declining even to thank him personally for his service after ordering the disbanding of the OSS. But Donovan's legacy and impact on the CIA were profound. Upon its establishment in 1947, one third of the CIA's staff were OSS veterans: ‘Files, funds, procedures, and contacts assembled by the OSS found their way into the CIA more or less intact.’ Four of the CIA’s future directors cut their teeth in the OSS. To this day, a statue of Donovan stands in the lobby of the Original Headquarters building, and the CIA claims that it ‘derives a significant institutional and spiritual legacy from the OSS’. Donovan's OSS provided a model for the peacetime global intelligence agency that was incrementally rebuilt after 1945 – an agency that engaged in espionage, open-source intelligence, research and analysis, all-source strategic assessment, counter-intelligence and, significantly, covert action. Over the past seventy years, covert actions, with their legacies stretching back to the jungles of Burma or the beaches of Normandy, have become synonymous with the CIA in popular myth. But transferring the experience and skills of wartime into a peacetime agency, and establishing a functioning bureaucratic and doctrinal model for their employment, took time. The centralisation of America's covert action function in the CIA has a somewhat convoluted history.

It begins with Donovan and the OSS. Prior to its entry into the Second World War, the US had not engaged systematically in covert action. The more established intelligence powers, like Britain or the Soviet Union, had engaged in subversive and paramilitary activities for decades. For them, the Second World War was an opportunity to hone and expand their skills. For the US, the war was a new departure in the way it conducted statecraft; the OSS led the way. As Michael Warner has outlined in his internal history of the OSS, the organisation conducted a broad spectrum of operations across multiple theatres. The men and women of the OSS cooperated and coordinated with the British, the French Resistance, with partisans across occupied Europe and North Africa and in parts of the Asian theatre.