Analyze the evolution of the Cold War between 1945 and 1949

After the end of the Second World War, the victorious Allies split the post-war world between them. With each superpower focusing on their personal ideological interests, historians have found critical information that would foreshadow future tensions between the Big Three. The harmony which once existed between the USSR and the USA began to wear thin as old suspicions came to the fore once again. Within the US, the American government was beginning to be influenced by hard-line anti-communists such as William Averell Harriman, the former US ambassador of the USSR and his advisor George F. Kennan. In a lengthy 8,000 word telegram, Kennan exposed his fear of Soviet aggression and their tentative bid for a Communist takeover in Europe. From that point on, the relations between the capitalist West and the communist East eroded to expose the threat of the development of a future World War. How did a chain of events lead to a period of global rivalry between the two new superpowers? In other words, how and why did tension develop in the 1940s that sparked the development of the Cold War?

[...] Moreover, evidence of future tension came to light, over what was to be done with Poland after the war was ended. When the Russian army entered Poland, they set up a communist government in Lublin, even though the initial government was in exile in London during the war. Therefore, as no agreement was reached on this point, would Roosevelt and Churchill trust Stalin to keep his word to set up a coalition government between London and Lublin while organising free elections in Eastern Europe? [...]

[...] In a speech before the establishment of the Truman Doctrine and the Marshall Plan, Truman announced the present moment in the world nearly every nation must choose between alternative ways [ ] one way of life is based upon the will of the majority [ ] the second way of life is based upon the will of a minority forcibly imposed upon the majority”. Here Truman, in a general agreement with the American government, concluded that communism thrived on chaos and poverty; the way to respond to it was to promote stability and prosperity through economic aid. [...]

[...] This was result of events taking place in Greece at the time where communists were trying to overthrow the monarchy, which had been restored by British troops in 1944, like agreed between Churchill and Stalin during the Percentages Agreement. Meanwhile, the British Foreign minister appealed to the USA and Truman declared that he “would support free peoples who are resisting subjugation by armed minorities or by outside pressure”. Greece immediately received massive amounts of aids and supplies which significantly contributed to the communist defeat. [...]