A) The 33rd president of the United States of American created the Truman Doctrine. The Truman Doctrine's policy was first put into action in 1947; their objective was to send U.S. aid to anti-Communist forces in Greece and Turkey. However, this policy expanded and the United States applied this policy to any countries that were threatened by Communism. Truman also developed the Marshall plan, it was plan to recover and stabilize Western Europe after the effect of World War II. The spread of Communist by the Soviet regime throughout Europe and Asia brought conflict between the USSR and the United States and this push the USSR and the Eastern European satellite states into the Cold War.
During the Second World War, the United States and USSR were allied against Germany. However, because of political different and distrust between these countries, the cooperation to keep peace began to fall after the war.
As well, wartime agreements were broken when the promises of both the USSR and the United States. The USSR promised that after the war their government would hold free election in Eastern Europe. The United States promised that they would supply the USSR with aid to help rebuild their destructed Cities. Stalin also took action in for Soviet security and wanted to create a buffer zone between Eastern Europe and the USSR. The Soviet Army began to invade and gain control of many areas of Eastern Europe. (Poland, Hungary, Yugoslavia, and Czechoslovakia) The United States did not approval of Stalin movement into Eastern Europe. In 1947 the United Kingdom were having financial crisis and therefore had to end their aid toward Greece. At the same time, the USSR was demanding naval station for Turkey, Bosporus and Greece was fighting against the Communist rebels in a civil war. The USSR had already expanded several communist government into Eastern Europe. Therefore, Truman applied the Truman Doctrine, which aided against the anti Communist forces in Greece and Turkey by sending troops. This Policy allows stabilization of legal foreign governments and also encourages Americans to fight in the Cold war. This policy expanded and the United States supported those nations who were threat of soviet expansionism. This lead into the formation of the containment doctrine. The purpose of this doctrine was to control the expansionism of Communism around the world by the United States and it's allies. This pushes the USSR into the Cold War because they saw the Truman Doctrine as an aggressive threat. Therefore, Stalin decided that Russia and the communist countries of Eastern Europe also not as the Soviet satellite states had to become stronger and linked together.
To carry out the United States goals, the United State created the Marshall Plan; this program was an economic aid to help rebuild western European economies. It seem that after the war the Communist opportunities were gaining because of it postwar economic status. The plans sent over 13 billion dollars into western European Economy and west of Germany. The USSR learned about the Marshall plan and where asks to cooperate with the capitalist of Western Europe. However, they were did not cooperate and believe that this plan was to spread capitalism ideology throughout Europe. Stalin saw that the Marshall Plan was anti-communist and he refused to have anything to do with it and created their own plan to put together their Communist States in Eastern Europe. To the USSR the Marshall Plan was a threat.. In 1949 the USSR created its own economic organization, which involved the Eastern European nations. This was known as the Council for Mutual Economic Aid or Comecon for short. It was nowhere near as successful as the Marshall Plan.