Truman at first was committed to following Roosevelt 's policies and priorities . He kept Roosevelt 's cabinet for a short while before putting in his own people . In 1945 Truman repeatedly rejected Churchill 's recommendations for a hard line against postwar Soviet expansion . Public opinion in America was demanding immediate demobilization of the troops . The policies followed were designed to benefit individuals , regardless of the damage it did when experienced military units lost their longest-serving and most experience soldiers . Truman refused to consider keeping an army in Europe for the purpose of neutralizing Stalin 's expansion . While Churchill and the U.S. State Department were taking an increasingly hard line , the War Department took a conciliatory position , led by Secretary Henry Stimson and General George Marshall . They rejected pleas and refused to allocate additional forces to Europe . In practice , the American forces were removed from Europe as fast as possible . By 1946 , however , Truman had changed . Disappointed with Stalin and the United Nations , And alarmed about Soviet pressures on Iran and Poland , he was accepting more and more advice from the State Department and was moving rapidly toward Churchill 's hard-line , Cold War position . The Soviet Union had become the enemy . When Truman took office , several international organizations that were designed to help prevent future wars and international economic crises were in the process of being established . Chief among those organizations was the United Nations , an intergovernmental organiza tion similar to the League of Nations that was designed to help ensure international cooperation . When Truman took office , delegates were about to meet at the United Nations Conference on International Organization in San Francisco . As a Wilsonian internationalist , Truman strongly supported the creation of the United Nations , and he signed United Nations Charter at the San Francisco Conference . Truman did not repeat Woodrow Wilson 's partisan attempt to ratify the Treaty of Versailles in 1919 , instead cooperating closely with Senator Arthur H. Vandenberg and other Republican leaders to ensure ratification . Cooperation with Vandenberg , a leading figure on the Senate Foreign Relations Committee , would be crucial for Truman 's foreign policy , especially after Republicans gained control of Congress in the 1946 elections . Construction of the United Nations headquarters in New York City was funded by the Rockefeller Foundation and completed in 1952
United Nations Conference on International Organization
United Nations Conference on International Organization
Foreign policy of the Harry S. Truman administration