The main cause of the Korean War, which erupted in 1950, stemmed from the division of Korea into two separate states following World War II. The North, supported by the Soviet Union and China, adopted a communist government, while the South aligned with the United States and pursued a capitalist system. Tensions escalated as both sides aimed for reunification under their respective ideologies. On June 25, 1950, North Korean forces invaded South Korea, leading to a military response from the United Nations, primarily the U.S. This conflict thus encapsulated the broader Cold War dynamics between communism and capitalism, resulting in a prolonged and devastating war.