The Korean War was primarily caused by a combination of ideological differences, the desire for reunification, and the geopolitical interests of global superpowers.

1. Ideological Differences: The division of Korea after World War II, with the North under communist rule led by Kim Il-sung, and the South under capitalist rule, marked the beginning of ideological tensions. The communist North sought to spread their ideology of socialism and reunify the entire Korean peninsula under a communist regime, while the capitalist South aimed to maintain its economic system and prevent the spread of communism.

2. Desire for Reunification: Reunification was a significant factor driving the conflict. Both North and South Korea desired to reunify the country under their respective systems. While the northern regime sought reunification on its own communist terms, the southern government aimed for a reunified Korea under a democratic system,

3. Geopolitical Interests: The Korean War also had significant geopolitical implications for the global superpowers of the time, the United States and the Soviet Union. The United States, viewing the spread of communism as a threat to its strategic position in East Asia, supported South Korea and sent military aid to prevent the communist North from taking over the entire peninsula. On the other hand, the Soviet Union provided support to North Korea, further intensifying the conflict. The Korean War served as a proxy battleground for the ideological and geopolitical struggles between the two superpowers.

These factors, ideological differences, the desire for reunification, and geopolitical interests, created a volatile environment that ultimately led to the outbreak of the Korean War.