The main cause of tension in the Cold War was ideological conflict between the United States and the Soviet Union. The U.S. aimed to promote capitalism and democracy, while the Soviet Union sought to spread communism. This fundamental disagreement led to various proxy wars, military build-ups, and political confrontations, as both superpowers sought to expand their influence around the globe. Key incidents, such as the Berlin Blockade, Korean War, and Cuban Missile Crisis, exemplified the escalating tensions and competition for global supremacy. The Cold War shaped international relations for decades, creating a polarized world, with nations aligning with either the Western or Eastern blocs.