Harry S. Truman:
Harry S. Truman was the 33rd president of the United States from 1945 to 1953, succeeding upon the death of Franklin D. Roosevelt after serving as vice president. He implemented the Marshall Plan to rebuild the economy of Western Europe, and established the Truman Doctrine and NATO.
The Truman Doctrine was an American foreign policy whose stated purpose was to counter Soviet geopolitical expansion during the Cold War. It was announced to Congress by President Harry S. Truman on March 29, 1947, and further developed on July 4, 1948, when he pledged to contain threats in Greece and Turkey. The Truman Doctrine implied American support for other nations allegedly threatened by Soviet communism. The Truman Doctrine became the foundation of American foreign policy, and led, in 1949, to the formation of NATO, a military alliance that is still in effect. Historians often use Truman’s speech to date the start of the Cold War.