Over the course of the American Occupation of Japan, the U.S. attitude toward the Japanese Communist Party (JCP) gradually shifted from one of friendly cooperation to one of mutual opposition. This new study examines the initial approach toward communism in Japan; internal and external factors that affected American attitudes; the various phases of the relationship; and how Japan ultimately became a democratic nation. Oinas-Kukkonen investigates American information gathering techniques used at the time to determine possible links with the Soviet Union. He also discusses the possibility that N.