What event led to the Cold War between the United States and the Soviet Union?

The Cold War emerged primarily as a result of post-World War II geopolitical tensions. Following the war, the United States and the Soviet Union became the two dominant superpowers, but they had fundamentally different ideologies—capitalism versus communism. The aftermath of the war saw the expansion of Soviet influence in Eastern Europe, leading to concerns in the U.S. about the spread of communism.

As countries in Europe were establishing their political systems, the U.S. aimed to promote democratic governments and capitalism, while the Soviet Union sought to strengthen communist regimes. This ideological divide fueled mistrust and competition, resulting in a tense standoff that shaped international relations for decades. The expression of these tensions unfolded through various events and policies, such as the Truman Doctrine and the Marshall Plan, aimed at containing communism, which solidified the rivalry and laid the groundwork for the Cold War itself.