This compact and accessible biography critically assesses the life and career of Dean Acheson, one of America’s foremost diplomats and strategists. As a top State Department official from 1941 to 1947 and as Harry S. Truman’s secretary of state from 1949 to 1953, Acheson shaped many of the key U.S. foreign policy initiatives of those years, including the Truman Doctrine, the Marshall Plan, the creation of the North Atlantic Treaty Organization, the rebuilding of Germany and Japan, America’s intervention in Korea, and its early involvement in the Middle East and Southeast Asia. Right up until his death in 1971, Acheson continued to participate in major policy decisions and debates, including the Cuban missile and Berlin crises and the Vietnam War.