Relations between the USA and Soviet Union underwent dramatic change in the years 1943-47. This is clearly demonstrated by the fact that they had gone from allies during the Second World War to a rivalry which went onto dominate the latter part of the twentieth century and world politics, in a period known as the Cold War.
This essay therefore hopes to analyse the key reasons that led to this breakdown in relations by looking chronologically at the long-term distrust suffered by nations, the growing and conflicting differences between Capitalism and Communism, the Soviet Expansion into Eastern Europe, the atomic bomb and finally the Marshall Plan in 1947. The first thing to point out is that relations between the USA and Russia had always been somewhat tense since the Bolshevik Revolution in 1917.
This is because Lenin and the communist party were very suspicious of America and the West after they intervened in the Russian Civil War by giving supplies and weapons to Russian groups who were against Lenin and communism. It can therefore be argue that there was a level of distrust even before the Second World War had begun. This is proved even more so by the fact that when Stalin had become leader in 1928, he had feared at first an invasion from the West because he was convinced Britain, France and the USA would ally with Germany and encourage Hitler to invade.
Furthermore this level of distrust continued during the world war two, as a conference was held in Teheran in 1943 in order to improve relations between the three allies. However this failed as the agreed Second Front was delayed, which worsened relations as Stalin was convinced that Britain and the USA were waiting for the Soviet Union to be seriously damaged by Germany.