Well before the Japanese attack on Pearl Harbor, Standley was strongly interventionist. He joined the staunchly pro-Allied Century Group in June 1940, publicly stating that the United States should recognize it was already effectively at war with Germany. In 1941, Roosevelt recalled Standley to active duty. His wartime responsibilities included defense planning for the Office of Production Management; service on the Roberts Commission investigating the Pearl Harbor attack; Navy Department public relations assignments; and membership in the Beaverbrook-Harriman mission, which provided Lend-Lease supplies to Soviet Russia.
In April 1942, Roosevelt appointed Standley ambassador to the Soviet Union. Soviet officials and American diplomats alike distrusted Standley's candid and forceful style, especially his insistence that the State Department not restrict the topics he might discuss with Soviet representatives. Apparently, Standley also resented the manner in which W. Averell Harriman, the president's special envoy, often conducted Soviet-American diplomatic negotiations independently of him. In May 1943, these assorted frustrations led Standley to submit his resignation, suggesting that Harriman replace him, and indeed this occurred when Standley returned to the United States in October. In March 1944, Roosevelt appointed Standley to the Office of Strategic Services Planning Group, where he remained until he was relieved from active duty in August 1945. Standley died in San Diego, California, on 25 October 1963.
Mayers, David. The Ambassadors and America's Soviet Policy. New York: Oxford University Press, 1995.; Standley, William H., and Arthur A. Ageton. Admiral Ambassador to Russia. Chicago: H. Regnery, 1955.; Walter, John C. "William Harrison Standley, 1 July 1933–1 January 1937." In Robert William Love Jr., ed., The Chiefs of Naval Operations, 89–99. Annapolis, MD: Naval Institute Press, 1980.