Throughout that time Acheson's was one of the most influential minds and strongest wills at work. It was a period that included World War II, the reconstruction of Europe, the Korean War, the development of nuclear power, the formation of the United Nations and NATO. It involved him at close quarters with a cast that starred Truman, Roosevelt, Churchill, de Gaulle, Marshall, MacArthur, Eisenhower, Attlee, Eden Bevin, Schuman, Dulles, de Gasperi, Adenauer, Yoshida, Vishinsky, and Molotov.