Forty years after the start of the Cold War, certain key issues remain unresolved: What precisely about the behavior of the Soviet Union after World War II did the U.S. perceive as a threat? Why did the Truman administration first endorse, then back away from, a strategy designed to avoid American military involvement in mainland Asia? Historian John Lewis Gaddis, one of the leading experts on postwar American foreign policy, explores these and other vital questions about U.S.-Soviet relations. Based on recently declassified American and British documents, his book offers a provocative reassessment of the course and effects of the Cold War.