By 1947 U.S.-Soviet relations had reached a new low. International arms control had proved futile, the United States had gone to the United Nations to pressure the Soviets to withdraw from Iran, and the rhetoric from both sides had become warlike. From the American vantage point, Soviet actions to expand communism in Eastern Europe appeared to threaten democracies in Western Europe. By contrast, the Soviets viewed the United States as seeking to extend economic control over nations close to their borders and to weaken communism in the Soviet Union.

Events in Greece allowed Truman to take the offensive and apply Kennan’s policy of containment. To maintain access to the Middle East and its Asian colonies, the United Kingdom considered it vitally important to keep Greece within its sphere of influence. In 1946 a civil war broke out in Greece between the right-wing monarchy and a coalition of insurgents consisting of members of the wartime anti-Nazi resistance, Communists, and non-Communist opponents of the repressive government. Exhausted by the war and in desperate financial shape, the British turned to the United States for help.

The Truman administration believed that the presence of Communists among the Greek rebels meant that Moscow was behind the insurgency. In fact, Stalin was not aiding the revolutionaries; the assistance came from the Communist leader of Yugoslavia, Josip Broz (known then as Marshall Tito), who acted independently of the Soviets and would soon break with them. Following Kennan’s lead in advocating containment, Truman incorrectly believed that all Communists around the world were ultimately controlled by the Kremlin.

While Truman was convinced that the United States had to intervene in Greece to contain the spread of communism, he still had to convince the Republican-controlled Congress and the American people to go along. To overcome potential opposition to its plans, the Truman administration exaggerated the danger of Communist influence in Greece. Truman sent Undersecretary of State Dean Acheson to testify before a congressional committee that “like apples in a barrel infected by one rotten one, the corruption of Greece would infect Iran and all to the east.” The administration’s presentation of the issues to the American public was even more dramatic. On March 12, 1947, Truman gave a speech to a joint session of Congress that was broadcast over national radio to millions of listeners. He interpreted the civil war in Greece as a titanic struggle between freedom and totalitarianism that threatened the free world. “I believe,” the president declared, “that it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures.” Truman’s rhetoric stretched the truth on many counts—the armed minorities to which the president referred had fought Nazi totalitarianism; the Soviets did not supply the insurgents; and the right-wing monarchy, propped up by the military, was hardly democratic. Nevertheless, Truman achieved his goal of frightening both lawmakers and the public, and Congress appropriated $400 million in military aid to fortify the existing governments of Greece and neighboring Turkey.

The Truman Doctrine, which pledged to protect democratic countries and contain the expansion of communism, was the cornerstone of American foreign policy throughout the Cold War. The United States committed itself to shoring up governments, whether democratic or dictatorial, as long as they were avowedly anti-Communist. Americans believed that the rest of the world’s nations wanted to be like the United States and therefore would not willingly accept communism, which they thought could be imposed only from the outside by the Soviet Union and never reasonably chosen from within.

Although Truman misread Soviet intentions with respect to Greece, Stalin’s regime had given him cause for worry. Soviet actions that imposed communism in Poland, along with the USSR’s refusal to withdraw troops from the Baltic states of Latvia, Lithuania, and Estonia, reinforced the president’s concerns about Soviet expansionism and convinced many in the U.S. government that Stalin had no intention of abiding by his wartime agreements. Difficulties in negotiating with the Soviets about international control of atomic energy further worried American foreign-policy makers about Russian designs for obtaining the atomic bomb.