At the end of World War II in 1945, Korea was set free from the occupation of Japan. Despite Cairo Declaration which meant the independence of Korea, Korea was divided into two parts at the 38th parallel, which crosses the midsection of the nation. American troops entered the Korean Peninsula to make North Korean Forces surrender in South while the Soviet Union Forces had a control in North.

   On August 13, 1950, a part of the Soviet 25th division landed in the Chung-Jin area, and they occupied Pyung-Yang on August 22. Meanwhile, the U.S. 24th division landed in In-Chon on September 15, 1950 and proceeded toward Seoul. By stationing troops in the Korean Peninsula, the Soviet Union and the United States aimed at controlling two Koreas in each part. However, although the allies had agreed at Cairo in 1943 that Korea would be free and independent, the border at the 38th parallel was soon sealed and the correspondence between the southern and northern zones ended.