THIRTY-EIGHTH PARALLEL. As World War II in the Pacific neared its end in August 1945, the United States began to dismantle the Japanese Empire and return conquered nations to indigenous rule. The United States had given little thought to the Korean peninsula before Japan's surrender. The region played a very minor role in America's strategic plan during the war, and many observers expected that the Soviet Union would assume the postwar occupation duties. However, Joseph Stalin's clear ambition to dominate Eastern Europe and parts of the Middle East convinced U.S. policymakers to limit Soviet influence in the Far East. The Soviet Union had 1.6 million battle-hardened troops on the Manchurian and Korean borders, but the United States wagered that Stalin would accept an American role in the postwar occupation of Korea if President Harry Truman's administration moved quickly.
When the Soviet Twenty-fifth Army entered Korea on 10 August and moved as far south as Pyongyang, the United States realized how little time it had to act. That same evening, the War Department instructed two U.S. Army officers, Colonel Dean Rusk and Colonel Charles H. Bonesteel III, to design an occupation plan for Korea. They proposed a demarcation line at the thirty-eighth parallel, with the Soviets handling the postwar occupation duties in the north and the Americans administering the southern half.
The choice was based on expediency—they were forced to make a quick decision and the thirty-eighth parallel was clearly marked on most maps of Korea. The decision was also made for bureaucratic convenience: the thirty-eighth parallel divided the country into two halves of roughly the same size (the northern part being slightly larger—48,000 square miles opposed to 37,000). However, it did not take into account the economic differences or such factors as demography and geography. As a result, the northern half included virtually all of the industrial facilities and mineral wealth, while the southern sphere incorporated most of the agricultural land and a majority of the population. The thirty-eighth parallel was designed to be a political border, but not a permanent one, and thus it did not take into account military defensibility. The United States immediately forwarded the occupation plan to Stalin and the Soviets accepted on 16 August. With the rapid ascent of the Cold War, however, the thirty-eighth parallel soon became a de facto international boundary between an emergent communist state led by Kim Il-sung in the north and a pro-Western autocratic state headed by Syngman Rhee in the south.
Hickey, Michael. The Korean War: The West Confronts Communism, 1950–1953. Woodstock, N.Y.: Overlook Press, 1999.
Sandler, Stanley. The Korean War: No Victors, No Vanquished. Lexington: University of Kentucky Press, 1999.
Stueck, William Whitney. The Korean War: An International History. Princeton, N.J.: Princeton University Press, 1995.
See alsoKorean War .