Under Japan’s surrender arrangements, the 38th parallel divided Korean surrender zones between Soviet and U.S. forces. Japanese troops north of the line were directed to surrender to Soviet forces, while troops south of it surrendered to U.S. forces.
The arrangement appeared in General Order No. 1, which directed Japanese forces across the former Japanese Empire to surrender to designated Allied commanders. In Korea, the 38th parallel became the boundary between the Soviet and American occupation areas after Japan’s defeat.
The line was not originally presented as a permanent international border. It was a military surrender and occupation boundary created at the end of World War II. Political tensions between the Soviet Union and the United States later hardened the division.
In 1948, separate governments were established: the Republic of Korea in the south and the Democratic People’s Republic of Korea in the north. The division became even more consequential after the Korean War began in 1950. The modern Demilitarized Zone is near, but not exactly identical to, the original 38th-parallel division.