Which event marked the beginning of Cold War tensions between the United States and the Soviet Union?

The end of World War II is considered the pivotal moment that marked the beginning of Cold War tensions between the United States and the Soviet Union. As World War II concluded in 1945, the alliance that had formed between the U.S. and the USSR during the war began to unravel. Differences in political ideologies became apparent, with the U.S. promoting capitalism and democracy, while the Soviet Union favored communism and a totalitarian regime.

Post-war Europe presented a major point of contention. The division of Germany into East and West, and the subsequent spread of Soviet influence in Eastern Europe, heightened fears in the U.S. about communism expanding globally. Relationships were strained further by events such as the Soviet Union's refusal to allow free elections in its occupied territories and aggressive moves in Eastern Europe, which the U.S. interpreted as a direct challenge to democratic values.

This period laid the groundwork for the Cold War, characterized by political rivalry, military tensions, and ideological conflict. Understanding this context is crucial, as it captures the origins of the prolonged struggle between the two superpowers that defined international relations for decades to come.