The U.S. and the 1945 Division of Korea

February 12th, 2012


During a meeting on August 14, 1945*, Colonel Charles Bonesteel and I retired to an adjacent room late at night and studied intently a map of the Korean peninsula. Working in haste and under great pressure, we had a formidable task: to pick a zone for the American occupation. . . . Using a National Geographic map, we looked just north of Seoul for a convenient dividing line but could not find a natural geographic line. We saw instead the 38th parallel and decided to recommend that. . . . [The State and War Departments] accepted it without too much haggling, and surprisingly, so did the Soviets. . . . [The] choice of the thirty-eighth parallel, recommended by two tired colonels working late at night, proved fateful.

- Dean Rusk (US Secretary of State under Presidents Kennedy and Johnson)

As Allied victory gradually became more certain during World War II, the plight of Korea slowly came to be addressed by the West. By 1943, the Franklin Roosevelt administration advocated international trusteeship for postwar Korea to protect the interests of the nations directly concerned with the peninsula and forestall potential conflict. It was thought a neutral Korea would best serve peace and stability in Asia and require Soviet-Chinese consent. At the Cairo Conference in December 1943, the U.S., United Kingdom and China proclaimed:

The aforesaid three great powers, mindful of the enslavement of the people of Korea, are determined that in due course [emphasis added] Korea shall become free and independent.

Britain had opposed mention of Korea at all, preferring to use it as a potential bargaining chip, and the American draft had stated “at the proper moment after the downfall of Japan, [Korea] shall become a free and independent country.” The compromise draft suggested by the British included the phrase “in due course,” which later angered Korean exiles who wanted immediate independence and wished to avoid Chinese tutelage. Soviet leader Joseph Stalin gave his approval to the Cairo communiqué on the Far East at the Teheran conference.

A general outlook prevailed among the Allies that 35 years of Japanese colonialism outweighed Korea’s long history of independent self-government. By 1944, the State Department began formulating concrete plans for Korea’s occupation and administration. That summer, the Roosevelt administration became convinced that Soviet participation in the Pacific theater would make Japan’s defeat far easier; but Stalin would not enter the war in Asia until victory in Europe was achieved.

At the fateful Yalta conference of February 1945, Stalin was offered concessions which acknowledged his preeminence in Northeast Asia in return for his eventual entry into the Pacific war. Stalin apparently believed trusteeship would not prevent Moscow from having decisive influence over postwar Korea.

The decision to divide Korea

Most scholars assert that Roosevelt was more concerned with maintaining the Soviet-American alliance than in keeping the Soviets out of Korea; perhaps Roosevelt was even ready to concede Korea as a Russian buffer state. Also, Roosevelt received no Soviet commitment to eventual Korean independence. Others insist that Roosevelt masterfully dealt with the problems with political realism; his two-fold concern was not only to win the war but win the peace. Roosevelt, in this view, deftly avoided once again making Korea the victim of great power rivalry by attempting to fashion a new balance of power in East Asia. In any case, Washington in the late months of the war did not consider Korea ready for self-government. Washington also did not hold a high opinion of the Korean exile movement, which violently opposed trusteeship and was bitterly divided internally.

A third school makes plain the practical reality that at Yalta, final military positions regarding the Far East were indeterminate. Concrete policy on Korea’s future simply could not be made. There had been little planning because most American military planners expected the war against Japan to continue for a few years. Until the manner and outcome of Japan’s defeat were clear, precise planning was impossible. Planning regarding Korea’s future indeed was already thin, and the American opinion of Korea’s incapacity for post-liberation self-governance made clear planning all the more difficult.

However, Soviet behavior in Eastern Europe after Yalta caused fears of expanding sovietization and began to undermine American confidence in a Korean trusteeship. American intelligence sources at that time indicated that over 100,000 Soviet-trained Korean guerrillas were ready for the liberation of Korea. Yet, the persistent factionalism within the Korean exile movement left Washington unable to find a capable and popular exile movement to support. Thus, trusteeship remained official U.S. policy, although some senior officials voiced their doubts in cabinet meetings. As part of this policy, Korea was unfortunately refused representation at the United Nations Conference in San Francisco (April-June 1945).

At the time of his death in April 1945, Roosevelt was still optimistic about Soviet-American cooperation despite sharp differences over Poland. His successor, Harry Truman, was far more suspicious of Soviet intentions. Within a week of assuming office, he reversed Roosevelt’s position on trusteeship and began to search for an alternative in Korea that could prevent Soviet expansion. Indeed, as historian James Matray put it, “Korea’s fate ultimately was tied to American military capabilities and Truman’s strategy for the defeat of Japan. If Stalin refused to endorse a Korean trusteeship, only prior American occupation of the peninsula could guarantee independence for Korea.

General Douglas MacArthur, Allied commander in the Pacific theater, urged an early frontal assault on Japan once the Soviets had entered the war and is said to have acquiesced to inevitable Soviet domination of Manchuria and Korea. However, other Truman advisors worried that once the Soviets entered the war, not only Manchuria and Korea would come under Moscow, but eventually China and Japan also. Truman was urged to soon meet with Stalin and British prime minister Winston Churchill to prevent an Allied split, and Korean trusteeship was considered an issue urgently in need of clarification. Meanwhile, Truman rejected State Department recommendations to withhold the Yalta concessions until Stalin promised to respect the sovereignty of China and Korea and favored MacArthur’s plan.

American military leaders continued to lobby for direct invasion of Japan along with Soviet entry as the best method to defeat Japan. They rejected a proposal to deploy forces in Manchuria and Korea as unjustified. Army Chief of Staff General George C. Marshall argued for Soviet military movement into Manchuria and Korea in order to accept the surrender of Japanese forces.

As Truman prepared for the Potsdam meeting that began July 17, 1945, final briefing papers urged that Korea not be invaded by only one of the Allies. Upon his arrival there, Truman received news of the successful testing of the atomic bomb in New Mexico. The possibility now loomed of early Japanese surrender as well as averting Soviet entry into the war. Yet, no firm agreement on Korea could be reached because the trusteeship question became entangled with unrelated issues or simply was avoided.

During the conference, General Marshall told his Soviet counterpart, General Alexei Antonov, that the U.S. did not contemplate a landing in Korea but would concentrate on landings in the Japanese main islands. However, he did caution the Russians that it would be politically inadvisable for either party to invade Korea alone. Nothing was agreed to on the multinational occupation of Korea, but the Soviets were forewarned that Korea was a lower priority for American military planners. Arguably, this gave the appearance of offering Korea to the Soviets. Moreover, a Marshall aide, General John E. Hull, suggested to the Soviets that the 38th parallel would be a suitable boundary between Russian and American land forces when they did enter Korea, but the question was not discussed.

Truman became hopeful that with the atomic bomb deployable in less than two weeks, victory over Japan would no longer require Soviet participation. Aware that the Soviets already were massing forces on the Chinese and Korean borders, Marshall knew the United States could not physically prevent the introduction of Soviet forces into Korea; he believed the U.S. should gain control of at least two ports. With his staff, Marshall settled upon the 38th parallel as a minimum policy objective, while still hoping that Japan’s quick surrender would obviate Soviet entry. The subject of trusteeship may have been deliberately avoided at Potsdam, presumably in the hope that it would become unnecessary if Soviet entry were forestalled. In the final protocol, despite Soviet urgings, no definite agreement on Korea was reached. The Allied commitment at Cairo in 1943 was simply reaffirmed in the Potsdam Declaration.

The Japanese surrender and Soviet entry into Korea

In the absence of a response from Japan to its July 28 ultimatum to surrender, the United States dropped history’s first atomic bomb on Hiroshima on August 6. Japan still did not surrender, and another bomb was dropped on Nagasaki on August 9. The day before, exactly three months from victory in Europe as they had promised at Yalta, the Soviets declared war on Japan. The Soviet intervention was unexpected by U.S. planners, many believing it would occur after mid-August, if at all; yet in view of the Soviet promise of entry by that date and the earnest Allied efforts to obtain their participation, it should have been anticipated.

Truman and his advisers, Harry Hopkins and W. Averill Harriman, were keenly aware that had the explicit subject of Soviet occupation of a portion of Korea been discussed with Stalin, he would have also insisted on a Soviet occupation zone in the northern Japanese island of Hokkaido and perhaps even in Manchuria. Soon after the Japanese surrender, the U.S. rebuffed all Soviet requests for such a zone in Hokkaido; yet in the case of Korea, no similar American effort was made to advise the Soviets to stay out.

The division of Korea

As Japan asked for surrender terms on August 10, Washington made one final attempt to prevent unilateral Soviet occupation of Korea. Secretary of State James Byrnes instructed the State-War-Navy Coordinating Committee (SWNCC) to construct a plan for the joint Soviet-American occupation of Korea, with the line as far north as possible.

Late the evening of August 10, meeting in the Pentagon, Col. Charles H. Bonesteel (later to command U.N. forces in Korea) and Col. Dean Rusk (later to become Secretary of State under Presidents Kennedy and Johnson), assigned to the Strategy and Policy Group of the Operations Division of the War Department, were given thirty minutes to devise a plan for dividing the Korean peninsula between the U.S. and USSR. What Bonesteel and Rusk kept in mind was that the nearest American troops were 600 miles away in Okinawa, while the Soviets had already entered northern Korea.

The issue for them was how to quickly create a surrender arrangement which the Soviets would accept while preventing their seizure of all Korea. Bonesteel wanted to draw the division around provincial boundaries so that the Japanese would clearly understand the demarcation. The only map of Korea available to them was a 1942 National Geographic map of “Asia and Adjacent Areas,” which did not denote provinces, only latitude and longitude. Rusk later confided that

they had seriously considered drawing the line between Pyongyang and Wonsan, at the narrowest waist of Korea and north of 38° latitude, but their map’s limitations precluded doing so with accuracy. Instead, they chose the 38th parallel. Moreover, the two colonels believed the division line was further north than they thought could realistically be reached by U.S. forces if the Soviets disagreed, but felt it vital to include Korea’s capital, Seoul.

Bonesteel and Rusk’s draft plan was reviewed after midnight by their superiors. One admiral, M. B. Gardner, proposed revising the draft to move the demarcation to the 39th parallel, which would have included the strategic Chinese port of Dalian as well as most of Korea. Gardner’s views were in line with the advice of Navy Secretary James Forrestal and Ambassador Harriman. But Brigadier General George A. Lincoln, the colonels’ boss, contended that the Soviets would not accept such a line nor could the U.S. reasonably hope to reach points further north. Assistant Secretary of State James Dunn supported Lincoln and considered this to be the view of Secretary of State James F. Byrnes. Thus the draft was sent to the full SWNCC, which on August 13 accepted the proposed division of Korea; then it was formally presented by Dunn to the Joint Chiefs of Staff for review. On August 14, the plan was signed by President Truman and communicated to General MacArthur the next day. As part of General Order Number One,

it stated:

The senior Japanese commanders and all ground, sea, air and auxiliary forces within Manchuria, Korea north of 38 degrees north latitude and Karafuto [Sakhalin] shall surrender to the Commander-in-Chief of Soviet forces in the Far East. The Imperial General Headquarters, its senior commanders, and all ground, sea, air and auxiliary forces in the main islands of Japan, minor islands adjacent thereto, Korea south of 38 degrees north latitude, and the Philippines shall surrender to the Commander-in-Chief, U.S. Army Forces in the Pacific.

The plan was telegraphed to Stalin, who accepted it without question on August 16, although the JCS were anticipating rejection and prepared to order the immediate occupation of Busan as a minimal U.S. objective. However, Stalin’s reply requested permission to accept the Japanese surrender on Hokkaido as well, below Sakhalin Island (the southern half of which was to be returned to Russia).

The Soviets, absent a stern American warning not to enter Korea, and in a superior military position, were generally deemed capable of occupying the entire peninsula before any American troops could get there. Only Stalin’s willingness, it is generally thought, to accept the surrender arrangement made possible the American occupation of southern Korea. However, according to historian Michael Sandusky, U.S. military planners thought the Soviets were capable of much more than was the case. He argues that the on-the-ground situation on August 15, 1945 in Korea and Manchuria was vastly different from what Washington perceived. He says:

In Korea, the meager Soviet forces were brought to a standstill in Chongjin [about 45 miles south of the Soviet border with Korea]. Few Soviet troops were in Korea and the ones that were there were pinned down by resolute Japanese troops.…[T]he Soviets were in no position to expand their presence in Korea.…In Korea, Soviet forces were still well above the forty-first parallel [above Kimchaek on the eastern coast].

Sandusky argues that given the naval and air transport capabilities the U.S. had at its disposal, key areas of Korea as far north as Hamhung (near the 40th parallel) could have been secured by U.S. forces had these areas been accorded the proper priority. At that point, the U.S. had an ability to move troops superior to the Soviets; in order to reach Pyongyang on August 24, the Russians even had to airlift troops. He implies that so much American attention was riveted on obtaining Japan’s surrender that military resources that could have been directed toward Korea were not.

Although the unexpectedly premature Soviet entry into the Pacific theater thwarted Truman’s hope to exclude the Soviets from Korea and its reconstruction, he thought he had registered a great success by obtaining Stalin’s concession on this arrangement. Stalin’s motivation apparently was to maintain Allied harmony so as not to arouse too much reaction to the sovietization of Eastern Europe. He hoped to partake or have equal voice in the Japanese occupation, and he was confident that trusteeship could lead to a pro-Soviet or “friendly” Korea. An American attempt to unilaterally seize Korea would have been gravely detrimental to overall Soviet interests. When, by late August, Harriman communicated to Stalin Truman’s refusal to allow Soviet participation in Japanese occupation, Stalin acceded. Stalin chose to respect the Korean arrangement despite Truman’s rebuff on Japan, and he instructed the Red Army to remain north of the 38th parallel; however, this portended that resolution of the Korean situation would become far more difficult, despite Truman’s outward optimism.

On September 7, MacArthur issued a proclamation to the people of Korea in which he declared the territory south of 38° north latitude and its people to be under his military authority as Commander-in-Chief, U.S. Army Forces, Pacific. He assured the Korean people that “in due course [emphasis added] Korea shall become free and independent,” and that “the purpose of the Occupation is to enforce the Instrument of Surrender and to protect them in their personal and religious rights.” On September 18, Truman issued a statement concerning Korean liberation. He proclaimed that the “building of a great nation has now begun with the assistance of the United States, China, Great Britain, and the Soviet Union, who are agreed that Korea shall become free and independent.”

Perspectives on Korea’s division

The division of Korea, however hasty and temporarily intended, is the seminal event of postwar Korean history. In his memoirs, Truman portrayed the decision to divide Korea at the 38th parallel as the consequence of military convenience and expediency in accepting the Japanese surrender. Although in immediate postwar years, a few suspected that the decision to divide Korea was made at Yalta or Potsdam, Truman’s account is accepted by most scholars, with the understanding that U.S. options were limited by the political and strategic realities.

A more critical view blames the U.S. for a policy of drift and vacillation, of oversight and blunder. Gregory Henderson put it succinctly:

No division of a nation in the present world is so astonishing in its origin as the division of Korea; none is so unrelated to conditions of sentiment within the nation itself at the time the division was effected; none to this day so unexplained; in none does blunder and planning oversight appear to have played so large a role. Finally, there is no division for which the U.S. government bears so heavy a share of the responsibility as it bears for the division of Korea.

A more common criticism, with perhaps contemporary relevance, is offered by historian Charles

M. Dobbs:

The confusions of wartime diplomacy would continue [in American policy toward Korea throughout the 1940s]; the hasty and sometimes incomplete decision-making process would reoccur. American officials would still find Korea of little strategic significance…. Of course, as the confusion continued, policymaking vacillated, and the situation would worsen or suddenly change. Similar to the hasty decision to occupy Korea at the 38th parallel without consideration of likely consequences, the internal situation of Korea, or the attitude of Soviet leaders, American officials would continue to merely react to the situation.…Throughout the 1940s, Korea would gain the attention of the harried men and women in Washington only when it seized the headlines…. In almost every case, policy would be made only for the short-term.…[T]he Soviets deserved the lion’s share of the blame for the ensuing controversy; but the U.S. government also deserves criticism for its failure to gain control of the situation, to plan ahead, to be prepared to act when the moment called for action. American officials should have recognized that…the peninsula would demand not just idle musings but serious, step-by-step planning.

Korean political scientist Won Sul Lee acknowledges many of these criticisms, and notes the comment by George McCune, in charge of the Korea Desk at the State Department at the time, who said, judging from the papers passing through his desk, that “almost no thought at all was given to Korea as a nation of more than 26 million persons.”

America’s self-conception of its role and interests in Korea have not been consistent but shifted and oscillated over the past half-century. Historically, the U.S. has not handled well many of the “big decisions” affecting Korea. One major problem that became manifest in 1945 was an overall low U.S. estimation of the strategic priority and importance of Korea, along with the notion that once liberated, its people would be incapable of self-government for a lengthy period. There appears to have been insufficient wartime analysis devoted to Korea, compared to that for Japan, China or the Soviet Union.

The division of Korea can also be said to manifest this low estimation of Korea’s importance. Korea’s lower priority was clear in Truman’s adamant refusal to allow Stalin military jurisdiction over Japan’s Hokkaido island without being similarly adamant about Korea. If it was impossible to keep the Soviets out of Korea altogether because of their short common border, the U.S. could have attempted to limit Soviet troops to the extreme northeastern part of the peninsula, to the exclusion of Pyongyang or the major port cities of Wonsan and Nampo. These rugged, mountainous northeastern Korean provinces might have proved largely inhospitable to a permanent Soviet presence.

Although over previous centuries the Korean peninsula had been the object of several designs by Japan, Russia and China to divide its territory, the 1945 partition of Korea was meant by the United States to be only a temporary division of the responsibilities for accepting the Japanese surrender and administering Korea until military occupation could end. It was not a design of conquest by any great power. Yet, Korea’s division has endured for 67 years, compounded by the Korean War, the Armistice and the creation of the DMZ. To paraphrase Edward Olsen, the Allies’ “in due course” commitment has been postponed indefinitely and remains unfulfilled. One hopes that this agony of division for one people can end before it enters an eighth decade.

*Other archival resources indicate the actual date was August 10, 1945.

Mark P. Barry is an independent Asian affairs analyst who has followed U.S.-DPRK relations for the last 22 years. He met the late President Kim Il Sung in 1994. He received his Ph.D. in foreign affairs from the University of Virginia.


Boose, Jr., Donald W. “Portentous Sideshow: The Korean Occupation Decision,” Parameters, Winter 1995

Dobbs, Charles M., The Unwanted Symbol: American Foreign Policy, the Cold War, and Korea, 1945-1950, Kent, OH: Kent State University Press, 1981

Dupuy, Trevor N., “New Perspectives on the Security of Korea,” Korean Journal of Defense Analysis, vol. I, no. 2, 1989 (see section on “Personal Background”)

Hasegawa, Tsuyoshi, Racing the Enemy: Stalin, Truman and the Surrender of Japan, Cambridge, MA: Belknap Harvard, 2005

Lee, Jongsoo James, The Partition of Korea of Korea After World War II: A Global History, New York: Palgrave Macmillan, 2007

Lee, Won Sul, The United States and the Division of Korea, Seoul: Kyunghee University Press, 1983.

Loh, Keie-Hyun, “Territorial Division of Korea: A Historical Survey,” Korean Affairs, April 1964.

Matray, James Irving, The Reluctant Crusade: American Foreign Policy in Korea, 1941-1950, Honolulu: University of Hawaii Press, 1985

Millett, Allan R., The War for Korea, 1945-1950: A House Burning, Lawrence, KS: University Press of Kansas, 2005

Olsen, Edward A., Toward Normalizing U.S.-Korean Relations: In Due Course? Boulder, CO: Lynne Rienner, 2002

Sandusky, Michael C., America’s Parallel, Alexandria, VA: Old Dominion Press, 1983.

Truman, Harry S, Memoirs. Vol. 1: Year of Decisions, Garden City, NY: Doubleday, 1955.

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About the Author

Mark Barry

Dr. Mark P. Barry is an independent Asian affairs analyst who has followed U.S. - DPRK relations for the past 22 years. He visited North Korea twice and met the late President Kim Il Sung in 1994, and has appeared on CNN to discuss North Korea. From 2005-06, he helped found and direct the Asia Pacific Peace Institute in Washington, DC. He also assisted the convening of the first-ever meeting of legislators from China and Taiwan in Tokyo in June 1989, under the auspices of the International Security Council. Dr. Barry has spoken on U.S.-DPRK relations before the Korean Political Science Association, Korea Institute of National Unification, and the Asia-Pacific Center for Security Studies in Hawaii, among others. He received his Ph.D. in foreign affairs from the University of Virginia and his M.A. in national security studies from Georgetown University. He teaches undergraduate and graduate courses in international relations and global management, and is also associate editor of the International Journal on World Peace quarterly.

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