The United Nations Offensive

The United Nations Offensive. 16 September - 2 November 1950.

"We must act now or die. We shall land at Inchon and I shall crush them." , General Douglas MacArthur

, At the end of the first campaign of the Korean War, General Douglas MacArthur was ready to attempt to repel what had been the sustained advance of the North Korean People's Army. General Walker's Eighth Army had been reinforced, its logistical support solidified, and it had checked the enemy along a defensive perimeter west and north of Pusan., The risk of a United Nations success was that it might provoke Communist China to enter the conflict. But in mid-September 1950, Chinese military involvement was not a major concern for either General MacArthur or President Truman. The focus was on breaking out from the Pusan Perimeter and engaging the North Koreans. MacArthur believed that the North Koreans' deep penetration to the Republic of Korea (ROK) made their forces vulnerable to an amphibious encirclement. His plan called for Maj. Gen. Edward Almond's X Corps to make an amphibious landing at In'chon, a port on the Yellow Sea well behind enemy lines. A force landing at In'chon would have to move only a short distance inland to cut North Korea's major supply routes, recapture the South Korean capital of Seoul, and block a North Korean retreat., The landing at In'chon was a considerable gamble. If it failed, MacArthur would be left with no major reserves and no prospect of immediate further reinforcement from the United States. Against light resistance, the amphibious landing was a success., Starting on 15 September, when a battalion of the 1st Marine Division, supported by air strikes and naval gun fire, captured Wolmi Island just offshore from In'chon, the X Corps divisions steadily moved inland toward Seoul., Meanwhile, on 16 September the Eighth Army launched its offensive. The ROK I and II Corps were positioned on the north of the Pusan Perimeter; the U.S. I Corps moved from the Taegu front; and the U.S. IX Corps was poised along the Naktong River. General Walker's forces moved slowly at first, but by 23 September the envelopment threatened by X Corps and Eighth Army became clear, and the North Koreans broke to the North. Seoul was liberated, and General MacArthur returned the capital to President Syngman Rhee on 29 September. By the end of September, the North Korean Army no longer existed as an organized force in the southern republic. The border along the 38th Parallel had been restored., The question now was whether to cross the 38th Parallel. To do so would clearly risk raising tensions with China and the Soviet Union. But the North Koreans still posed a threat: some 30,000 troops had escaped from the South, and an additional 30,000 were in Northern training camps. President Truman and the Joint Chiefs of Staff gave cautious initial approval. At the beginning of October the ROK I and II Corps crossed the 38th Parallel, moving up the east coast and through central Korea. On 9 October an all-out offensive began after the United Nations General Assembly voted for the restoration of peace and security throughout Korea, thereby tacitly approving the occupation of the North. On that day General Walker's U.S. I Corps crossed the border in the west., On 19 October the I Corps' 1st Cavalry Division and the 1st ROK Division entered P'yongyang, the North Korean capital., On the 24th, General MacArthur ordered his commanders to advance as quickly as possible with all forces available, so that operations could be completed before the onset of winter. The pres of the Eighth Army in the west was relentless, as it sent separate columns north toward the Yalu River. On the 26th an ROK regiment sent renaissance troops to the town of Ch'osan, becoming the first UN element to reach the Yalu., Meanwhile, General Almond's X Corps had been withdrawn from combat to prepare for new amphibious landings, this time on the east coast of the peninsula. The rapid advance of ROK forces above the 38th Parallel and the fall of Wonsan, North Korea's major port, allowed the 1st Marine Division to make an unopposed landing at Wonsan on the 26th of OCtober; on the 29th the 7th Division landed unopposed at Iwon, eighty miles farther north. Adding the ROK I Corps to his command, General Almond then attacked up the coast and inland toward the Yalu and the Chanjin (Chosin) Reservoir, focusing on the industrial, communications, and irrigation centers of northeastern Korea. As one American newspaper put it, "Except for unexpected developments...we can now be easy in our minds as to the military outcome.", But then the unexpected did happen. Resistance stiffened in the last week of October. On the 25th an Eighth Army ROK unit near Unsan, northwest of the Ch'ongch'on River, captured a Chinese soldier. The extent of Chinese infiltration was not clear, but over the next eight days, Chinese forces dispersed the ROK troops who had reached the Yalu, battered the 8th Cavalry Regiment of the 1st Cavalry Division near Unsan, and forced the ROK II Corps to retreat. Time would quickly demonstrate that this was not just a temporary setback. The nature of the conflict would now fundamentally change.