The partition of Korea was formally begun when Japan was defeated in World War II. During the conflict, the leaders of the Allies debated what would happen to Korea when Japan was defeated. The decision to liberate Korea from Japanese domination was made by the leaders. However, the Koreans would be placed under an international trusteeship until they were declared ready for self-rule.
In the latter stages of the war, the US proposed splitting the Korean peninsula into two US and Soviet occupation zones along the 38th parallel. The Soviet Union accepted their proposal to partition Korea in half.
When Did Korea Split?
When Japan was defeated in World War II, the partition of Korea formally started. Leaders of the Allies discussed what would happen to Korea once Japan was defeated during the war. The decision was made by the leaders to free Korea from Japanese rule. However, until they were deemed prepared for self-rule, the Koreans would be placed under a global trusteeship.
The US proposed dividing the Korean Peninsula into two US and Soviet occupation zones along the 38th parallel during the closing phases of the conflict. Their suggestion to divide Korea in half was approved by the Soviet Union.
The Korean Peninsula was divided along the 38th parallel north from 1945 to 1950, and the Military Demarcation Line from 1953 until the present.