The main cause of the breakdown of relations between the U.S. and the Soviet Union was ideological differences compounded by events during the Cold War. The fundamental division was between capitalism, as represented by the United States, and communism, embodied by the Soviet Union. Following World War II, tensions escalated through various conflicts, including the arms race, the Korean War, and differing views on European recovery and expansion of influence in the developing world. Key incidents, such as the Cuban Missile Crisis in 1962, exacerbated these tensions, crystallizing the adversarial relationship that characterized much of the late 20th century.