Following the Second World War, the Soviet Union was clearly becoming a global power. They had seized Berlin and cutoff the Western side from all goods. President Truman felt that the Soviet Union was a threat to world peace and sought to alleviate the situation by whatever means possible. Truman attempted to do so by creating the Truman Doctrine, the Marshall Plan, and NATO. These doctrines and institutions help stop Soviet territorial advances and spreading their spheres of influence. .
In 1947, President Truman drafted the Truman Doctrine, which allocated large sums of money to assist Greece and Turkey. Both countries were facing communist threats in their country, and in order to ease the aforesaid threats, economic and military aid was provided by the United States. Truman felt the best way to solve the communist threat in these countries was to strengthen their respective incumbent governments.
The next year, in 1948, the Marshall Plan was penned. The Marshall Plan allotted seventeen-billion dollars to the reconstruction of postwar Europe. The majority of Europe was in shambles, as most of the countries were poverty-stricken. It was not uncommon for nations like these to develop a communist push. The influx of large amounts of money truly helped to diminish the threat.
Finally, in 1949, the North Atlantic Treaty Organization was created. NATO was an alliance of eleven non-communist nations who pledged full support for each other. The main idea was that if any of the NATO countries were attacked, they would have to answer to the United States. The threat of United States aggression unquestionably deterred the Soviets from spreading their influence.
President Truman knew very well that it would be excruciatingly difficult to wipe out communism as we know it. He felt the best that realistically could be done was to contain it. Truman did so successfully by providing financial aid to countries threatened by communism.