Study Guide

The Korean War Analysis

  • War

    A War in Three Parts

    The first six months of the Korean War witnessed three stunningly successful surprise attacks. Each one nearly led to total victory:

    • first for the North Koreans
    • then for the Americans
    • then for the Chinese

    The North Korean Advance

    The first great surprise attack of the Korean War was the one that started it: North Korea's sudden full-scale invasion of the South on June 25th, 1950. 

    The poorly-trained, poorly-equipped, poorly-organized forces of South Korea's unloved leader Syngman Rhee immediately collapsed under the North Korean onslaught. Kim Il Sung's North Korean communist army, benefiting from superior training and weaponry provided by the Soviet Union, moved quickly southward through the countryside, expecting to be greeted as liberators by South Korea's rural peasantry. 

    While those hopes largely proved unfounded, several crack units of the South Korean military did defect to the North. And those South Korean police and soldiers who remained loyal to Syngman Rhee devoted nearly as much time and energy to hunting down and murdering Rhee's domestic political opponents—perhaps as many as 100,000 of them, just during the summer of 1950—as they did to defending their country from the North Korean attackers. 

    As a result, the South Korean capital of Seoul fell to communist forces just four days after the invasion began. In less than a month, North Korean forces gained control of almost the entire country, with South Korean troops—and their American allies, just beginning to arrive in Korea—confined to a small area around Pusan, at the very southern tip of the Korean Peninsula.

    But the communists couldn't quite finish the job. 

    In the first days of August, American and South Korean troops finally managed to establish a firm defensive line—the "Pusan Perimeter"—and halt the North Korean advance. With more and more well-trained, well-armed American soldiers pouring into the Pusan area from overseas, the prospects for North Korean victory began to fade. Throughout August, the Americans—now outnumbering their opponents in manpower, tanks, and artillery, and maintaining a total monopoly in air power—turned back a series of desperate North Korean attacks aimed at ending the war. 

    At the same time, however, the Americans had no success in pushing forward directly into the North Korean lines.

    The Inchon Landings

    On September 25th, the Americans struck back with a spectacularly successful surprise attack of their own. General Douglas MacArthur—ignoring earlier declarations by figures as powerful as Joint Chiefs Chairman Omar Bradley that "large-scale amphibious operations will never happen again"—organized one of the largest and most successful amphibious attacks in American military history.

    MacArthur deployed a huge task force of more than 300 ships carrying nearly 70,000 men to carry out a surprise attack on the port of Inchon, far to the north of the Pusan battle zone. If it could be captured, Inchon, located on the west coast of Korea near the original border between North and South, would offer easy access to the captured South Korean capital of Seoul. 

    More important, a beachhead at Inchon would offer American forces a brilliant opportunity to cut off vital supply lines and routes of retreat for the bulk of the North Korean Army, deployed far to the south at the Pusan Perimeter.

    MacArthur's gambit to open up a huge new offensive hundreds of miles behind enemy lines caught the North Koreans totally by surprise. The massive invasion force quickly overwhelmed the light defenses left in place by the communists at Inchon. Within days, American troops liberated Seoul and began wreaking havoc against North Korean forces strung out between Pusan and the 38th parallel. North Korean troops that had held the line for a month at the Pusan Perimeter fell quickly into disorganized retreat, fleeing for the relative safety of North Korean territory. 

    But American and South Korean troops waited along all corridors of retreat, inflicting grave casualties in so-called "mop-up operations" against panicked and disorganized enemy forces. Fewer than half of the 70,000 communist soldiers deployed to Pusan in August 1950 ever made it back to North Korea. 

    In less than two weeks, in the second half of September, the once-fearsome North Korean military virtually ceased to exist as an effective fighting force.

    Advance and Reverse

    The survival of South Korea now appeared to be all but guaranteed. The only question was whether American forces should push on, moving beyond the 38th parallel to try to liberate all of Korea from communist control. 

    With the North Korean Army in tatters, it seemed that nothing stood in the Americans' way. MacArthur, hoping to cement his reputation as one of the great military geniuses in American history, had no reservations about pushing on to total victory. 

    Truman, hoping to restore his reputation and resurrect his fading presidency by leading the United States to a great triumph over a communist foe, was just as enthusiastic about taking the fight to the North. On September 27th, Truman ordered MacArthur to advance into North Korea, proceeding as long as he didn't encounter Soviet or Chinese opposition and he remained confident of victory.

    As Truman's orders suggested, the only real danger was that an expansion of American war aims from the rescue of the South to the destruction of the North might cause either Russia or China—enemies vastly more powerful than Kim Il Sung—to intervene directly in the conflict. 

    But neither Truman nor MacArthur thought such a prospect was likely. Soviet or Chinese intervention might have been decisive earlier in the conflict, the Americans reasoned, when it might have allowed Kim to complete his victory before the Americans could organize an effective defense. But if the Chinese and Soviets hadn't come in then, why would they do so now, when prospects looked so bleak and defeat looked so likely? Besides, with American aircraft in total control of the skies over the Chinese-Korean border, any incursion by Chinese forces across the Yalu River would face devastating bombing attacks. 

    When Truman and MacArthur met on October 15th at Wake Island to coordinate strategy for the final phase of the war, the general confidently reported, "We are no longer fearful of [Chinese] intervention. We no longer stand hat in hand."blank">Cold War still lingers on along the barren strip of demilitarized land dividing communist North Korea from the anticommunist South. Along the 38th parallel, it's always 1950.

  • Politics

    A Strange Kind of Salvation in Korea

    When North Korea's army suddenly launched a full-scale invasion of the South in June 1950, throwing an already tense international situation into outright crisis, American policymakers reacted with understandable alarm, scrambling to organize an immediate military response. 

    At the same time, however, several top figures in the Truman administration saw the Korean crisis not only as a threat, but also as an opportunity—or perhaps even an unlikely kind of salvation. Looking back on the frenzied events of June 1950 with several years' hindsight, Secretary of State Dean Acheson—the most powerful figure in President Truman's foreign policy brain trust—offered an unexpected analysis. 

    "Korea," he said, "came along and saved us."blank" href="https://www.shmoop.com/historical-texts/checkers-speech/adlai-stevenson.html">Adlai Stevenson in the general election to become the 34th President of the United States. Like MacArthur, Eisenhower had been a five-star general in World War II, becoming a national hero by organizing the successful D-Day invasion of Normandy, France in 1944. 

    But as military officers, Eisenhower and MacArthur couldn't have been more different. Where MacArthur was brash, "Ike" was humble. Where MacArthur was bold, "Ike" was cautious. Eisenhower's calm and steady persona served him well in the 1952 campaign, when Korea still loomed as a major—perhaps the major—issue. Without offering any specifics, Eisenhower simply promised "I shall go to Korea" to arrange a speedy and honorable end to the war. Voters elected him in a landslide.

    So, a war that began as a potential source of salvation for Democratic President Harry S. Truman ended with the sweeping electoral victory of the first Republican president since 1928.

  • Diplomacy

    A Tale of Two Koreas

    Sandwiched between Japan to the east, Russia to the northeast, and China to the northwest, the 600-mile-long Korean peninsula lay at the heart of Asian imperial rivalries throughout the 20th century, just as it had for thousands of years before. 

    For most of the first half of the 20th century, Korea was annexed and exploited by Japan, the burgeoning imperial power of the East. The Japanese suppressed local rebellions with extreme brutality and simultaneously established some modern infrastructure on the peninsula in order to take advantage of the rich mineral deposits in North Korea. 

    Japan's defeat in World War II finally brought Korea independence. Of a sort.

    Little actual fighting occurred in Korea during the Second World War, as the critical battles pitting the United States against the Japanese Empire occurred farther to the south. In July 1945, the leaders of the victorious Allied nations—the United States, Great Britain, and the Soviet Union—met at Potsdam, Germany, to make plans for the establishment of a new postwar world order. 

    The fate of Korea was something of an afterthought, as most of the conference focused on contentious issues regarding what to do with Eastern Europe. But the Allies did agree that Japan should be forced to relinquish control over Korea, and that the country should be jointly occupied by the U.S. and USSR, with the 38th parallel serving as a temporary boundary between the Soviet and American zones of occupation. 

    As late as August 9th, 1945—three days after the atomic bombing of Hiroshima and just six days before Japan's surrender—there were no Allied forces in Korea. On that date, the Soviets began their invasion from the north, meeting virtually no resistance as the Red Army moved southward through Korea. The Americans didn't begin to organize their own occupation until a month later, so the Soviets easily could have occupied the entire peninsula. But the Red Army halted its advance at the 38th parallel, carefully honoring the spirit and letter of the agreement reached at Potsdam by waiting patiently for their American friends to occupy the southern half of the country.

    But the temporary wartime friendship between the Soviet Union and the United States was already beginning to fall apart. 

    Korea soon became a pawn in a much larger game, as acrimony between the victorious superpowers transformed World War II Allies into Cold War enemies. By May 1946, international negotiations designed to reach an agreement on Korea's unified future broke down amidst the heightening tensions of the Cold War

    The Soviets wanted to ensure that the country would be ruled by a friendly communist government; the United States insisted, just as forcefully, that Korea not fall under total Soviet control. Both refused to relinquish control over their zones of occupation, so what had been intended as a temporary division at the 38th parallel began to look more permanent.

    In the North, with Soviet assistance, Kim Il Sung began organizing an authoritarian communist regime. Meanwhile, in the South, Korean exile Syngman Rhee—who had spent much of his life living in the United States—established his own administration, no less authoritarian than Kim's but ferociously anticommunist and backed by the Americans. 

    The newly established United Nations attempted to resolve the matter in late 1947, when it created a temporary commission to supervise elections in order to reunify Korea as one independent country. But the communists boycotted the elections, allowing the unpopular Rhee to win, with a dubious mandate, in the South, while no elections at all were held in the North. 

    By the fall of 1948, South Korea under Rhee had declared itself the independent Republic of Korea. North Korea then proclaimed itself the People's Democratic Republic under Kim's rule. The South received recognition from the western powers and the UN, while the Eastern Bloc recognized the North. The governments of both Kim and Rhee claimed to represent the entire country, and both were eager to reunify Korea under their own leadership—by force, if necessary.

    Civil War

    Between 1946 and 1950, Koreans endured a vicious undeclared civil war in which communist and anticommunist insurgents slaughtered each other with increasing brutality. Historians now estimate that more than 100,000 Koreans died during this period—all killed by other Koreans, all before what Americans usually consider to be the beginning of the Korean War proper in June 1950. 

    During this phase of guerilla fighting, Kim's communists seemed to have the upper hand, but only just slightly. Many Koreans, even non-communists, objected to Rhee's apparent willingness to accept partition of the country and his over-reliance on American aid to support his regime. 

    Kim, by contrast, seemed to have stronger nationalist credentials and insisted absolutely upon the need to reunify the country. Several of South Korea's best army units defected, en masse, to the communists. Still, Kim's seeming advantage in the civil war wasn't enough to topple Rhee's government, and the prolonged guerilla violence made it impossible for Korea to begin rebuilding its economy and infrastructure, long neglected by Japanese occupation. 

    By 1950, Korea was, in the words of historian Walter LaFeber, little more than "a Cold War-wracked country which lacked nearly everything except authoritarian rulers, illiteracy, cholera epidemics, and poverty." 

    Most importantly, the crucial decision to throw American ground troops into the Korean conflict was made by President Truman on June 27th, 1950—several hours before the UN Security Council passed its resolution (by a vote of 7 to 1, with Yugoslavia opposing and India, Egypt, and the Soviet Union abstaining) authorizing international intervention in Korea. 

    That the United Nations allowed itself to be drawn into the Korean War as something of a pawn of the United States proved that Franklin Roosevelt's original idea that the organization could serve as the cornerstone of a cooperative world order was well and truly dead. In the Cold War, superpower conflict rather than international cooperation would be the most powerful force shaping global diplomacy. The UN's participation in the Korean War was less a sign of its strength than its weakness.