In 1941, six months before the attack on Pearl Harbor, he enlisted in the United States Navy. He worked in the Navy's censor's office until he managed to transfer to the Office of Strategic Services in 1943. He was first stationed in Cairo where he spent an uneventful year. After Cairo he spent three months in Turkey, and in August 1944 transferred to Romania, where he became head of OSS operations in southeastern Europe. Wisner arrived just as Romania joined the Allies and declared war on the Axis. His first task was to oversee the return of some 1,350 American airmen who had been shot down in missions against Romanian oilfields. The POWs were returned by a U.S. Air Crew Rescue Unit via the Popeşti-Leordeni Airfield. Twelve B-17 Flying Fortress planes flew out the prisoners in hourly shifts. In all, some 1,700 American POWs were transported. In March 1945, Wisner was transferred to Wiesbaden, Germany. In 1945–1946, he returned to law practice at Carter, Ledyard & Milburn.
CIA
Wisner was recruited in 1947 by Dean Acheson to join the State Department to become the Deputy Assistant Secretary of State for Occupied Areas. On June 18, 1948, the United States National Security Council approved NSC 10/2 which created the Office of Special Projects. On September 1, 1948, the office was formally established, although it was renamed to the Office of Policy Coordination for obfuscation purposes. Wisner was chosen to lead the OPC in the capacity of Assistant Director for Policy Coordination. The OPC initially received services from the CIA but was accountable to the State Department. According to its secret charter, the OPC's responsibilities include "propaganda, economic warfare, preventive direct action, including sabotage, antisabotage, demolition and evacuation procedures; subversion against hostile states, including assistance to underground resistance groups, guerrillas and refugee liberation groups, and support of indigenous anti-communist elements in threatened countries of the free world." During the early 1950s, Wisner was the subject of FBI inquiries in connection with his wartime work in Romania, including the claim that he had an affair with Tanda Caradja, daughter of Romanian princess Catherine Caradja during the war; Caradja was alleged in FBI reports to be a Soviet agent. However, Wisner was cleared of all suspicions by the CIA Office of Security. On August 23, 1951, Wisner succeeded Allen W. Dulles and became the second Deputy Director of Plans, with Richard Helms as his chief of operations. In this position, he was instrumental in supporting pro-American forces that toppledMohammed Mossadegh in Iran in 1953 and Jacobo Arbenz Guzmán in Guatemalain 1954. J. Edgar Hoover and U.S. Senator McCarthy succeeded in forcing CIA director Allen W. Dulles to dismiss one of his key staff members, Carmel Offie, in 1953 over Wisner's objections. Wisner worked closely with Kim Philby, the British agent who was also Soviet spy. Wisner was also deeply involved in establishing the Lockheed U-2 spy plane program run by Richard M. Bissell Jr. Wisner suffered a serious breakdown in September 1958. He was diagnosed as manic depressive and received electroshock therapy. Richard Bissell replaced Wisner as Deputy Director of Plans. After a lengthy recovery, Wisner became chief of the CIA's London Station. In 1961, Wisner was ordered to organize CIA activities in British Guiana. In 1962, Wisner retired from the CIA.
Family
Wisner married Mary Ellis 'Polly' Knowles and they had four children: Elizabeth Wisner, Graham Wisner, Ellis Wisner, and Frank G. Wisner who entered into diplomatic service.