After World War II ended in 1945, a new kind of rivalry began. The United States and the Soviet Union disagreed about how countries should be run. The Soviet Union wanted to spread communism, where the government controls everything. The United States supported democracy, where people choose their leaders. In 1947, Greece was fighting a civil war. Communist rebels were trying to take over the government. Turkey also faced pressure from the Soviet Union. Both countries were running out of money and weapons. President Harry Truman asked Congress for $400 million to help Greece and Turkey. On May 22, 1947, he signed the policy into law. Truman told Congress that America must support free peoples who resist being taken over. This idea became known as the Truman Doctrine. It was a major turning point. Before this, America had mostly stayed out of other countries' problems. The Truman Doctrine committed the country to stopping communism from spreading. It shaped American foreign policy for the next forty years.