Final answer:
Kim Il Sung invaded South Korea in an attempt to reunify the Korean peninsula under Communist rule.
Step-by-step explanation:
Kim Il Sung invaded South Korea as part of his plan to reunify the Korean peninsula under Communist rule. After World War II, Korea was divided into two zones, with the Soviet Union controlling the north and the United States controlling the south. Kim Il Sung, with support from the Soviet Union, believed that the United States would not intervene if he invaded the south.
The invasion of South Korea by North Korean troops on June 25, 1950, led to the Korean War. The United Nations, with the United States as the main contributor, intervened to support South Korea, while the Soviet Union and China supported North Korea. The war eventually ended in a stalemate, with a ceasefire agreement signed in 1953.