When the Korean War broke out on June 25, 1950, what began as a civil war soon became a Cold War crisis involving major world powers. The U.S. and its allies, unified under the flag of the United Nations, backed South Korea while the Soviet Union and China supported North Korea. The war would devastate the Korean peninsula, lead to an expanded U.S. military presence worldwide, and end in a frustrating stalemate that resolved nothing.
The U.S. and the USSR divided Korea into two occupation zones after World War II. Various attempts to unify the country under one government failed in disagreement over whether Korea should have a democratic or communist government. Finally, the North Korean regime under Kim Il Sung decided to reunify the country by force and install a communist government. The North Korean’s main attack quickly crushed South Korean defenses and captured the capital, Seoul on June 28, 1950.
On June 26, the UN Security Council adopted a resolution demanding that North Korea withdraw their forces to the 38th Parallel and authorizing the use of force to help South Korea. The U.S. took the lead to defend South Korea. But post World War II demobilization had left the U.S. military a shadow of its former self. By August, U.S. and UN forces had been driven back to the Pusan Perimeter, a 140 mile line surrounding the last pocket of resistance. Korea was on the edge of collapse.
U.S. General George MacArthur devised a plan to attack the North Koreans from the rear by making an amphibious landing at Inch’on, just twenty-five miles east of Seoul. The plan was risky: the Yellow Sea tides are extreme and the channel approaches to Inch’on are narrow. The landing zone was far from ideal and troops would have to climb a sea wall in the middle of a built up area. Senior U.S. military leaders worried that if the attack failed MacArthur would not have enough troops to continue to fight.
MacArthur’s gamble paid off. Landing forces swept ashore on September 15 against light resistance and moved inland. The North Korean Army retreated in a panic, and MacArthur, with dramatic ceremony, returned the capital city to the South Korean President Syngman Rhee on September 29.
MacArthur soon turned his attentions northward and ordered the Army to cross the 38th Parallel into North Korea to destroy the North Korean army, occupy North Korea, and clear the way for UN action to unify Korea. Leaders were wary that China or the Soviet Union might enter the war, so MacArthur was told to exercise caution and halt his advance short of the Yalu River (the border between North Korea and China) if it looked like China or the Soviets might intervene. The North Korean army had ceased to function effectively, and as the Allies moved north most people thought the war was almost over.
Unfortunately, despite the warning signs, few leaders thought that either the Soviets or Chinese were willing to risk war. Unknown to MacArthur, some 300,000 well-camouflaged Chinese soldiers had slipped into North Korea undetected and were waiting to spring their trap. On the night of November 25, 1950, the Chinese launched a massive attack. Two days later they hit the U.S. left flank at the Chosin Reservoir, and by the next day the UN position in North Korea began to crumble.
The Army’s withdrawal from North Korea was one of the greatest ordeals ever suffered by U.S. forces. The Chinese surrounded 30,000 U.S. and UN troops near the Chosin Reservoir. For 17 days, the Allied troops fought a raging battle in bitter cold as they struggled southward, inflicting heavy casualties on the Chinese as they trudged along. The U.S. 2nd Infantry Division emerged from the battle with one-third of its men dead, wounded, or missing. With most of their equipment lost or abandoned, the division staggered back to South Korea to refit.
The Chinese advanced well into South Korea but met stiff resistance once the surprise wore off. Eventually UN forces fought their way back north. The battle line fluctuated for a time then settled into a bloody stalemate near the Imjin River.
Few citizens wanted a long war, and American leaders worried that the war could spread globally and lead to nuclear war. President Truman thought that between the Army’s northward advance and the heavy casualties they had inflicted on the enemy, the Communists might be willing to negotiate. The UN’s mission to eject the invaders from South Korea had been achieved. Truman thought that was good enough.
MacArthur disagreed and said so publicly. His relationship with the commander-in-chief had often been rocky, and Truman could not ignore this direct challenge to presidential authority. Concluding that MacArthur was “unable to give his wholehearted support to the policies of the United States government and of the United Nations in matters pertaining to his official duties,” Truman fired MacArthur and named General Matthew Ridgway his successor. Ridgway’s orders included authorization to engage in peace talks with North Korea.
Negotiations were difficult and broke off several times. Both sides agreed that fighting would continue until an armistice was signed and that the existing front lines would become the new boundary between North and South Korea. Fighting soon tapered off to patrol clashes, raids, and small battles for possession of outposts in No Man’s Land. Ridgway ordered an “active defense”: the Army was to establish an outpost line forward of its current main line of resistance, fortify both lines, patrol aggressively, and use its firepower to inflict maximum casualties on the enemy. Troops could counterattack to retake lost positions but could not mount larger operations without permission.
The peace talks stalled over several issues, including treatment of prisoners of war. Thousands of Korean and Chinese prisoners held by the UN had been forced into the military and had no desire to return to North Korea or China, but their governments wanted them back. American leaders believed they had a moral duty to give prisoners a choice. The Communist delegates protested vigorously, and the resulting impasse deadlocked negotiations until 1953. Meanwhile, the fighting continued.
The final agreement created a neutral commission to handle the POW issue and created the De-Militarized Zone between North and South Korea that remains one of the most heavily fortified borders in the world today. Fighting ceased on July 27, 1953, but because the cease-fire agreement was never followed by a formal peace treaty, the war technically never ended. In the aftermath of the war, Americans realized they had new responsibilities in the post-war world and could not return to pre-World War II era isolationism. For the first time in history, Americans accepted that we would have to maintain a large standing Army in a high state of readiness pre-positioned around the world to contain a global threat.
Over 36,000 U.S. Soldiers lost their lives in the Korean War. More than 92,000 were wounded, 7,200 were taken prisoner, and more than 8,000 were missing and have still not been recovered.
Adapted from Stewart, Richard W., ed. “Chapter 8: The Korean War, 1950-1953.” American Military History Vol. II: The United States Army in a Global Era, 1917-2003. Washington, DC: Center of Military History, 2005. pgs. 217-250. http://www.history.army.mil/books/AMH-V2/AMH%20V2/chapter8.htm.