مبدأ ترومان
The 1947 Truman Doctrine was part of the United States' political response to perceived aggression by the Soviet Union in Europe and the Middle East, illustrated through the communist movements in Iran, Turkey and Greece. As a result, American foreign policy towards the USSR shifted, as George F. Kennan phrased it, to that of "containment". Under the Truman Doctrine, the United States was prepared to send any money, equipment, or military force to countries that were threatened by the communist government, thereby offering assistance to those countries resisting communism. In U.S. president Harry S Truman's words, it became "the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures".