Why did North Korea invade South Korea in June 1950?

North Korea invaded South Korea in June 1950 primarily to reunify the Korean Peninsula under communist rule. Following the division of Korea at the 38th parallel after World War II, both the North and South established separate governments in 1948, each claiming legitimacy over the entire country and threatening to unify it by force.123

By 1950, North Korean leader Kim Il-Sung had become convinced that a war was necessary for reunification. After building the Korean People's Army into a formidable force with Soviet assistance, Kim secured approval for the invasion from Soviet leader Joseph Stalin. While some historical perspectives suggest Kim acted on his own initiative to pursue a unified communist state, others indicate that Stalin approved the plan to keep Kim dependent on the Soviet Union or to create a strategic diversion for the United States. The invasion began on June 25, 1950, marking the start of the Korean War.1423