Fears of communism had risen after the Second Red Scare, led by Wisconsin US Senator Joseph McCarthy, indirectly calling for a policy to limit Communist Threat: NSC 68. In accordance with NSC 68, a report that stated that all communist activities were controlled by Soviet Premier Joseph Stalin, and it called for military and economic aid to any country deemed to be resisting Communist threats, the Americans sent troops to South Korea after it was invaded by the North on June 25, 1950. That contradicted the report, in that the United States was once again at war (the report stated that the United States should avoid war), but US President Harry S. Truman feared a domino effect and wanted to prevent the spread of communism: