38th parallel

Two usages

The term "38th parallel" names two things at once: the line of latitude at 38° north, and the effective boundary that divided Korea from 1945. The period recorded for this entry (1945–1953) applies to the latter, the span in which the parallel functioned as the line of division. The line of latitude itself persists irrespective of the war.

How the line was drawn

On 8 August 1945 the Soviet Union declared war on Japan and its forces advanced into Manchuria and northern Korea. Fearing that Soviet troops would occupy the whole peninsula, the United States hurried to fix occupation zones. One account states that James Dunn, chairman of the State-War-Navy Coordinating Committee (SWNCC), directed the Army's Operations Division (OPD) on 11 August 1945 to find a military demarcation line that would place Seoul and Incheon under American occupation as Soviet forces moved south, and that Colonel Charles Bonesteel and Colonel Dean Rusk drew the 38th parallel on a National Geographic map hanging in the OPD and reported it back, the proposal reaching MacArthur as part of General Order No. 1. Neither man was a Korea expert, and no Korea expert was consulted.

The details, however, do not agree across sources. Rusk's own 1991 memoir dates the map session to "the night of 14 August 1945, the day of Japan's surrender," and has him knowing only that Seoul should be in the American zone and that the US Army did not want an excessive occupation area. Against this stand accounts that the two were tasked on 10 August, that Korean Wikipedia dates the SWNCC instruction to 11 August, and that Russian Wikipedia states the line was agreed at the 38th parallel on 10 August. The phrase "two young officers" is also imprecise: one source calls them young officers, while others identify them as Colonel Bonesteel and Colonel Rusk.

The limits of "no prior plan"

That the line was picked on the spot is supported by several sources, but occupying Korea in divided zones had been discussed before. In July 1945 the US Army's Operations Division had already drawn up a plan for a four-power occupation of Korea by the United States, the Soviet Union, Britain, and China, and in August the Joint War Plans Committee's JWPC 385/1 set out a divided administration with the four powers garrisoning key strategic points. That draft was not adopted, over the military's objection that such an occupation was unfeasible; only the revision of 22 September, JWPC 385/5, fixed partition at the 38th parallel, excluded Britain and the Republic of China, and reduced it to a two-power division. The line Rusk and Bonesteel drew was acceptable because it fitted a conception already under examination.

When was it decided? A conflict among sources

Reputable sources disagree on the time and place of the decision. Britannica states that "US military planners chose it at the Potsdam Conference" in July 1945. The US State Department's Office of the Historian says only that during the Second World War the United States and the Soviet Union agreed to divide Korea temporarily at the 38th parallel to supervise the surrender of Japanese forces. Russian Wikipedia states that the line was agreed at the 38th parallel on 10 August 1945. "Potsdam" and "Washington, 10–14 August" cannot both be right. Neither the Yalta Conference of February 1945 nor the Potsdam Conference of July–August 1945 contains any agreement on dividing Korea at the 38th parallel: the question was not on either agenda.

Rusk's own testimony, and its limits

Rusk wrote that he knew the 38th parallel "made no sense economically or geographically" and that Korea had enjoyed unity and a high degree of geographic continuity for the better part of a millennium, but that under Cold War conditions "military expediency" had to rule the day. He also said that had he known Korean history he would "almost surely" have chosen a different line. One qualification is needed: some accounts state that Japan and pre-revolutionary Russia had once discussed sharing Korea along the same parallel, but the two men in 1945 are said not to have known of it. That precedent cannot be used to show careful deliberation over the line; it illustrates the carelessness of the decision. Even the map is described differently: Rusk's memoir quote says only "using a National Geographic map," while other treatments of the same material add "small-scale."

From temporary measure to division

The partition was not permanent in intention. The United States proposed dividing Korea into Soviet and American occupation zones in order to negotiate a trusteeship with the Soviet Union, and in December 1945 the Moscow Conference of Foreign Ministers agreed on a five-year, four-power trusteeship for Korea. When bilateral Soviet-American negotiations then failed, the only agreed framework for a unified Korea lapsed. In May 1946 crossing the 38th parallel without authorization was made illegal, and the joint Soviet-American commissions of 1946 and 1947 made no progress against Korean opposition to trusteeship and the deepening Cold War. Some documentation from 1945 suggests the Soviet government initially had no plans for a permanent division. As separate regimes took shape under Syngman Rhee in the south and Kim Il-sung in the north, the division hardened.

The line divided more than territory. It followed no river or mountain range, cutting through villages, families, and institutions, and it became a "hot" frontier that was difficult to defend, with frequent border clashes. The division placed roughly half the population on each side, sixteen million in the American zone and nine million in the Soviet zone. Rusk stated that he had weighed the shortage of available American troops, together with constraints of time and space, and judged that reaching far north before Soviet forces arrived would be difficult.

War and armistice

Even before the war the 38th parallel was already a hot frontier, and in 1949 border incidents peaked; the northern side claimed more than 2,600 armed infiltrations from the south. Fighting along this line widened into full-scale war in June 1950: on 25 June the Korean People's Army crossed the 38th parallel and the Korean War began, and Seoul fell within three days. The war was at once an international conflict and a civil one, and the causes and character of its outbreak remain disputed among sources.

The UN Command intervened with the recovery of the 38th parallel as its objective, but Syngman Rhee argued that the northern attack had invalidated the boundary, and MacArthur stated his intention to unify Korea. On 1 October 1950 southern forces crossed the parallel, and American and UN troops followed a week later, despite Chinese warnings of intervention.

The line was contested in the armistice talks as well. The communist side supported a ceasefire line based on the 38th parallel, while the UN side supported a militarily defensible line based on the areas each side held. China and the Democratic People's Republic of Korea initially expected the ceasefire line to remain at the 38th parallel, but eventually agreed to take as the boundary not that parallel but the line of military contact, the Kansas Line. The Armistice Agreement concluded at Panmunjom on 27 July 1953 established the Military Demarcation Line and a Demilitarized Zone 4 kilometres wide as the new boundary dividing North from South. The armistice is purely a military document to which no nation is a signatory; the Republic of Korea never signed it, because of Rhee's refusal to accept a divided Korea, and no peace treaty followed at the 1954 Geneva Conference, so no final peace settlement was reached.

The armistice line is not the 38th parallel

The Military Demarcation Line lies near 38° north, but unlike the 38th parallel it runs south in the west and north in the east. As a result Ongjin and Yonbaek counties of Hwanghae Province and the city of Kaesong and Kaepung County, all south of the parallel, went to the Democratic People's Republic of Korea, while Yeoncheon County of Gyeonggi Province and the counties of Cheorwon, Hwacheon, Yanggu, Inje, and Yangyang in Gangwon Province, lying north of it, went to the Republic of Korea; Goseong County was split between the two. Here one can see how a question internal to the nation was settled by the interests of outside great powers.

The limits of "its role came to an end"

Even after the Military Demarcation Line and the Demilitarized Zone became the new boundary, the name "38th parallel" did not disappear. Because of its symbolic weight and its place as the direct origin of the division, the Military Demarcation Line is still commonly called the "38th parallel." The claim that the parallel "ended its role as the effective dividing line" is therefore correct as to the physical boundary but only partly correct at the level of name and symbol. Korean Wikipedia also dates the existence of the 38th parallel from 2 September 1945 to 25 June 1950, treating it as no longer functioning as an effective boundary after June 1950. Other accounts carry the period through to the armistice, so the end date depends on which level is meant.