What triggered beginning of the Korea war?

The Korean War began on June 25, 1950, when North Korean forces, supported by the Soviet Union and China, launched a surprise invasion of South Korea. Tensions had been escalating since the end of World War II, when Korea was divided along the 38th parallel into two separate states: communist North Korea and capitalist South Korea. The invasion aimed to reunify Korea under communist rule, prompting a response from the United Nations, led by the United States, to defend South Korea. This conflict marked the beginning of a significant Cold War struggle in the region.