The Korean Peninsula had been a battlefield for centuries and this episode begins with an overview of the wars fought from the first through the 19th century and shows how the country developed as forged through conflict. The 1904 Sino-Russian War, with the peace deal brokered by U.S. President Theodore Roosevelt led to Korea being dominated by and eventually occupied by Japan. At the end of World War II, the Russians were in the North and the Americans in the South, roughly separated by the 38th Parallel. In 1947 and 1948 U.N. resolutions basically set up what became the North and South Korean nations as proxies for the Soviets and the U.S. in Asia and laying the foundation for war by the North’s leader Kim Il Sung.
All through the late 1940’s North Korean leader Kim Il Sung pushed on Stalin, the leader of the Soviet Union, to sanction and support an invasion of South Korea. With the victory of the Communists on the Chinese civil war in 1949 and continued pressure from Kim, Stalin agreed to April 1950. The north invade South Korea on June 25, 1950 and in a matter of days had overrun the South Korean forces and the few American forces and pushed past Seoul far into the south. The U.N. placed all forces under the command of General Douglas MacArthur, who realized only American ground forces could turn the tide. The problem: The U.S. Army, which was 8,000,000 strong in 1945 was now only at 500,000 and the Marine Corps down to 75,000. With the beleaguered South Korean and American forces pushed south to Pusan in the southeast corner of the peninsula, American troops began to arrive from the Army divisions stationed in Japan to reinforce this last bastion: The Pusan Perimeter.
American, Republic of Korea and U.N. troops were holding the Pusan Perimeter in the summer of 1950 as the North Korean invasion had pushed through all of the country. This became the last line of defense while the U.S. was pushing men and materiel into the area. One of the first units was the 1st Provisional Marine Brigade with 6,000 Marines that arrived in Pusan in August 1950.
General MacArthur devised a bold plan to outflank the NKA forces and retake Seoul and cut off the NKA forces from their supplies lines from the north. This was the plan for the Inchon landings. Since the forces that comprised 10th Corps – the 1st Marine Division and the Army’s 7th Division – represented MacArthur lasts reserves, the initial reaction from the Joint Chief was skeptical since if the landings didn’t work out well, there were no more reserves to engage the NKA in theater. MacArthur convinced the Joint Chiefs and the Inchon landings took place with the U.N. forces rapidly moving inland and retaking Seoul. At virtually the same time, the forces in the Pusan Perimeter broke out and the U.N. forces drove the NKA all the way out of the South past the 38th Parallel. The question then was: Would the U.N. forces invade the North?
The U.N. forces had driven the NKA out of the South past the 38th Parallel (the diving line between South and North Korea) and began pursuit into the North with the objective of destroying the remaining NKA forces. The losses the NKA suffered in the South were huge: Losing 150,000 men and another 125,000 taken prisoner. With U.N., and especially American forces, now in the North, the political leaders of Communist China and the Soviet Union became quite concerned; fearing that a successful campaign against the NKA would leave foreign forces on their borders.
U.N. forces were moving through North Korea, having pushed the NKA back across the 38th Parallel. The 1st Marine and 7th Infantry divisions, comprising X Corps, were moving toward the village of Hagaru-ri, rested near the southern tip of the Chosin reservoir. The Chinese entered the war with ground forces supported by Soviet air forces and multiple divisions engaged the 1st Marines. What became a major battle saw the outnumbered Marines hold off the Chinese 9th Army Group and then make a fighting withdrawal with the battle of the Chosin Reservoir becoming one of the most storied exploits in Marines Corps lore.
The U.N. forces in the eastern part of North Korea, mostly U.S. Marines and Army infantry, were being pulled out of North Korea to the coast to Hungnam to leave North Korea. This was a fighting withdrawal, especially for the 14,000 Marines and infantry moving from Yudam-ni and Toko ri towards the Funchinlin Pass. They contended with at least four Chinese divisions and fought several pitched battles along the way to the coast, especially at Hill 1081 near Funchilin Pass. The last Marine senior officer to leave the pass was Chesty Puller.
During the withdrawal from the North, the vastly outnumbered U.N. forces – mostly U.S. Marines and Army infantry – fought 4 Communist Chinese armies with 14 divisions and inflicted over 38,000 casualties. In December 1950 the debate among the U.S. government, the United Nations and General MacArthur was either to pursue a limited war or escalate. With the Chinese already involved, President Truman and the U.N. decided not to escalate. General Matthew Ridgeway was appointed new commandeer of the 8th Army in Korea and began to prosecute the war base on attrition: Killing Communist soldiers rather than taking ground. The concept was to wear out the enemy forces and utilize the superior fire power available to the U.S. and U.N. forces. During the early months of 1951 the Chines mounted several offensive operations and all were countered and in fact the Chines and NKA forces were again pushed back above the 38th Parallel and Seoul, for the 4th and last time, changed hands and was firmly in control by the U.S., U.N. and South Korean forces.
In 1951 General MacArthur was advocating an escalation, including an attack into Communist China, besides and embargo and air attacks. This was counter to the Administration’s and UNC’s strategic goals of bringing the Communists to the negotiating table through attrition. Macarthur became more openly critical of President Truman, and this eventually ended his career as Truman relieved him of command on April 11, 1951. General Matthew Ridgeway was appointed as the new supreme UNC commander. At the front, Chines forces launched a new offensive with 14 divisions and the UNC forces used maneuver and attrition to not only decimate the attackers but drive them back into North Korea inflicting huge casualties. On the political front, Mao and Stalin agreed it was now time to negotiate and the Soviets announced that talks would begin on July 10, 1951 among the various parties to the conflict. Meanwhile, fighting continued with both sides trying to win ground and optimize their lines for any future cease fire. While negotiations were going on, some of the bitterest fighting on the war would take place.
At the end of 1951 and into 1952, the Korean War looked like World War I: Static front lines. A Main Line of Resistance (for both sides). A No Man’s Land in between. Basically the UN forces and the Communist forces manned outposts on the hills surrounding the lines of resistance and the war became a series of battles for control of these high ground outposts., with several changing hands many times. Eventually the peace talks resumed in Panmunjom and in July 1953 an armistice was signed. No peace treaty was ever signed. Both South and North Korea claim sovereignty over the entire Peninsula and the Demilitarized Zone (at the 38th Parallel where it all began) is the most heavily fortified border in the world.