During the Cold War, both USA and USSR have faults. But Stalin's action was most to blame. He has the most aggressive actions compared to the actions done by USA. He did not keep his promise which he had agreed at the Yalta Conference. He had dominated the countries in East Europe and spread Communism, causing dictatorship and people imprisoned due to the disloyalty towards Stalin. Also, a lot of Stalin's actions had offense USA. However, things done by Truman such as the propagandas posted and increased weapons plus army force was only to defend USA from attacks by other countries.
Stalin did not do as The Big Three, Churchill, Roosevelt and himself, agreed at the Yalta Conference. They agreed that they would hunt down and punish any war criminals who were responsible for the horrors of the Nazi concentration camps. But due to the non-aggression pact signed by Hitler and Stalin in 1939, Stalin did not send any troops to help USA to hold back Hitler in Russia.
This worried USA because it was a sign that Stalin was not standing at a totally opposite of Hitler. Under this relationship, Stalin might betray USA and Britain which he should not do. They had also agreed to hold free elections for people to choose the government they wanted to be in their countries. But Stalin set up communist governments in the countries in Eastern Europe. He ignored the wishes of the majority of the people. These actions had offended the agreement between The Big Three.
Stalin had not act according to USA and Britain's expectations either. USA did not expect that Stalin was not withdrawing the Soviet troops in Eastern countries such as the Baltic States, Finland, Poland. Stalin did not listen to Britain and the USA's protest...