The major ideological rivalry that characterized the political landscape from the post-World War II era to the 1990s was the Cold War, primarily between the United States and the Soviet Union. This geopolitical tension encompassed military, political, ideological, and cultural conflicts, with both superpowers championing competing systems: capitalism versus communism. The Cold War led to significant events like the Korean War, the Cuban Missile Crisis, and the Vietnam War, fundamentally shaping international relations and influencing global policies. The rivalry also sparked an arms race and space race, ultimately ending with the dissolution of the Soviet Union in 1991.