Truman Doctrine announced

On March 12, 1947, President Harry S. Truman addressed a joint session of Congress in Washington and asked for million in aid for Greece and Turkey. Truman argued that Britain could no longer sustain anti-communist forces in Greece or help Turkey resist Soviet pressure in the eastern Mediterranean. The speech announced what became known as the Truman Doctrine, a commitment that the United States would support free peoples resisting armed minorities or outside pressure.

The doctrine marked the decisive turn from wartime alliance with the Soviet Union to the policy of containment in the early Cold War. Truman, Secretary of State George C. Marshall, and congressional supporters believed that a communist victory in Greece or a Soviet breakthrough against Turkey would shift the balance of power in the Mediterranean. Republican critics questioned the cost and reach of the commitment, but the administration treated the request as a test of whether the United States would accept a permanent global role after 1945.

Congress approved aid to Greece and Turkey in May 1947, giving the Truman Doctrine immediate legislative force. The same logic of containment soon produced the Marshall Plan in 1948 and NATO in 1949, turning Truman's March 1947 speech into the opening statement of postwar American foreign policy.