Why did the wartime alliance between the US and Soviet Union unraval?

The wartime alliance between the US and Soviet Union unraveled due to deep-seated ideological differences, with the US promoting capitalism and democracy while the Soviet Union championed communism. Post-World War II, competing interests in Europe led to tensions, as the Soviets sought to expand their influence in Eastern Europe, sparking fears of communism in the West. Events such as the Berlin Blockade and the onset of the Cold War further exacerbated these divisions, ultimately leading to a prolonged period of hostility and rivalry.