 World War II came to an end in September 1945 with the Surrender of Japan, and relations with the Soviet Union became a central matter of foreign policy.Various issues, including the fate of post-war governments in Europe and Asia and the administration of the United Nations, had already begun to strain the wartime alliance between the Soviet Union and the United States.Critics of the Soviet Union objected to the oppressive satellite states that the Soviet Union established in Eastern Europe and Soviet involvement in the Greek Civil War and the Chinese Civil War.