After World War II, the United States and the Soviet Union became enemies and entered a Cold War. The two countries had been allies in the fight against Nazi Germany, but tension developed as the two countries emerged from the war as global powers. The allies had come together out of necessity, not desire. While the Soviet Union sought to spread communism, capitalist America adopted a policy of containment. Their growing mutual suspicions led to the Cold War, an indirect conflict that arose from the fear of nuclear destruction and was fought by each country supporting different international conflicts through aid and acquisitions. As allies during World War II, the United States and the Soviet Union allied themselves against the Nazi power. In a joint message of assistance to the Soviet Union in 1941, Roosevelt and Churchill wrote to their ally regarding the urgency of defending against Nazi attack and their intention to send supplies (Document A). Although the countries had a common interest in defeating Nazism, tensions over disagreements existed during the war. The following year, Stalin, in a memorandum to aides, wrote about the opening of a second front in Europe. After Churchill declared the organization of another front impossible and the United States supported him, Stalin expressed his intention to do so and said that Churchill's position was a “moral blow” to the Soviet Union (Document B). After the war, the United States and the Soviet Union turned into enemies as common ground disappeared and the United States criticized the policies of the Soviet Union. In Our Russian Ally (1945), Vera Micheles Dean discusses the differences between the two countries with opposing governing ideals. He states that to resolve differences, Russia should participate in international agencies to explain its intentions (…… half of document……rs!” (Document H). The Soviet Union and its communist nations of Eastern Europe created a rival alliance called the Warsaw Pact. This created a political division of Europe that worsened the Cold War. In response to the growing conflict, the United States introduced the Marshall Plan to help nations with which it had positive relations and assist them in rebuilding infrastructure. In conclusion, post-World War II conflict arose between the United States and Russia due to growing mistrust between the two opposing nations. The Cold War was fought between the United States and the Soviet Union as both attempted to spread their policies government to other countries through conferences and changes in control of post-war Europe, the two nations acted against each other to preserve their countries' interests and sought to outmaneuver each other in a post-war power race..