Battle at Chosin Reservoir: Turning Point in the Korean War

By the mid-20th century, America had established itself as the world’s preeminent military power, having achieved numerous combat victories during the First and Second World Wars. American forces, led by General Douglas MacArthur, entered the Korean War conflict in July and August of 1950 with confidence and an unmatched military record. But everything would change at the Chosin Reservoir on November 28th, 1950.

As World War II ended in the mid-1940s, the state of Korea was caught up in an escalating world conflict known as the Cold War. Following the fall of the Nazi Reich in 1945, the wartime alliance between the Soviet Union and Western nations, particularly the United States, swiftly began to break down. Disputes between the former allies resulted in new borders being drawn between communist and capitalist nations. A line was drawn from Europe to the eastern borders of Asia, including the Korean peninsula.

Following the defeat of the Japanese empire, Korea, which had been a possession of Japan since 1910, was occupied by the Allies and divided into administrative zones, with the Soviet Union responsible for the North and the United States for the South. The border was drawn at the 38th parallel, across the middle of Korea, and remains in the same spot today. In 1948, after attempts to forge a unified Korean state failed, each zone formed its own government, with the Soviet Union and the United States extending support to their political counterparts.

Both sides claimed to be the sole legitimate government of all of Korea and aimed to unify the peninsula, which led to partisan conflict, particularly within the ROK. On June 25th, 1950, tensions hit a boiling point, and the DPRK launched a full-scale invasion of South Korea. The invasion provided the United States with a new opportunity to confront the communist spread.

In the aftermath of World War II and the San Francisco Charter of 1945, the United Nations (UN) was created to reduce the chances of another global conflict through a council for all world powers, where disputes could be resolved without resorting to military force. The DPRK’s invasion of the ROK thus presented a severe early challenge to the UN’s capacity to prevent and resolve conflict, especially since key members of the UN’s core Security Council backed opposing sides. Nevertheless, the UN made the decision to intervene directly and created the United Nations Command (UNC) on July 7th, 1950. Consisting mostly of US and British troops under the command of Douglas MacArthur, this collective force aimed to confront and repel the DPRK.

Within weeks, American forces stationed in Japan and on the U.S. mainland would begin moving into South Korea. By November, America and its allies had successfully pushed North Korean forces back well beyond the 38th parallel. Indeed, the UNC intervention was so successful that many DPRK soldiers were pushed across the border into China. The world, and especially the UNC, believed that victory was within their grasp. Little did they know, events would soon take a turn for the worse.

Intelligence and Developments Outside DPRK

Meanwhile, largely unbeknownst to the UNC, China was making plans to enter the conflict. UNC intelligence believed there were only 30,000 Chinese troops positioned on its perimeter. While there were clashes in early November, they concluded the Chinese forces posed no major threat. In reality, the Chinese numbered in the hundreds of thousands and were positioned within and around UNC perimeters. The miscalculation by the UNC at the time was twofold. First, their enormous underestimation of the number of Chinese soldiers within the area and, second, their decision to ignore or brush off the possibility of a military intervention from a powerful communist neighbor.

All of this would come to a head at the Battle of the Chosin Reservoir in late November. As 16,000 American soldiers, consisting mostly of the 1st and 7th US Marine divisions, settled in areas around the reservoir, a large Chinese army of 150,000 gathered to launch a surprise attack on the night of November 27th, 1950.

Chinese forces had the element of surprise, and the 1st, 5th, and 7th Marine divisions soon found themselves in a precarious situation. Upon their arrival in the town of Hagaru, days before the attack, Marines began construction of an airstrip so supplies could be flown in. These supplies were to be stockpiled and used in the coming offensive against the DPRK. However, the Chinese forces struck before the Americans were able to resupply.

Indeed, their lack of material was so acute that even as Chinese forces attacked, American forces continued to build the airstrip while under enemy fire. While the town of Hagaru was being attacked, Marines in Koto-ri, Hudong-ni, Yudam-ni, and other areas around the reservoir also came under fire. Wave after wave of Chinese soldiers threw themselves at the lines of American soldiers. Some Chinese soldiers would break through, but the Marines were able to hold and defend their perimeters.

The weather would further complicate the situation for both sides. Although winter had not officially begun, temperatures had consistently stayed cold, dropping as low as negative 25 degrees Fahrenheit. Regardless of their winter gear, many Marines suffered from severe frostbite. Some would even lose their toes due to exposure.

Chinese soldiers were even more poorly equipped than the Marines. Most of the regular Chinese forces were assigned a two-piece uniform made of quilted cotton with a cotton cap. Footwear was also poor quality. They, like their American adversaries, experienced numerous cases of frostbite. While these circumstances were challenging, the cold weather surprisingly helped the injured by freezing their wounds shut. This allowed American and Chinese soldiers to continue fighting in this harsh weather for the next two weeks.

In the days following the initial Chinese assault, while the airstrip was under construction, supplies for the 1st and 7th Marine divisions were desperately short. One Royal Marine unit from Britain, Task Force Drysdale, located south of Hagaru in Koto-ri, attempted to bring aid. Around 300 men and many vehicles left for Hagaru but were ambushed by Chinese soldiers. The re-supply mission slowed considerably due to weather and almost constant engagement with Chinese forces. By the time they reached Hagaru on November 28th, they had lost 61 men and 71 vehicles, but even with these losses, the American Marines welcomed the aid. The collective UNC force located in Hagaru would have to hold out for another two days until they could be resupplied by air.

Up until this point, the consensus amongst American leadership and media was that the war was practically won. General MacArthur especially felt the repercussions of his disregard for a potential intervention from China. The confidence and optimism MacArthur held only days before would spiral downward as the battle unfolded. Pressure mounted when US media headlines stated that American forces stationed around Chosin had been destroyed. The media even posed the question of whether this new development would lead to another world war. The US public was uneasy with how events were unfolding around Chosin, and while questions proceeded to be pondered at home, US marines and their allies continued in their fight for survival.

Breakout

By early December, it became apparent that all UNC personnel around Chosin needed to retreat south. As retreat was called, Marines around Yudam-ni and Hudong-ni gathered their few remaining supplies to regroup with those at Hagaru-ri. From there, they would move about 11 miles south to Koto-ri and onward a further eight miles to the Funchilin pass, where they hoped to be free from enemy harassment. However, the UNC forces were under no illusions. With extreme weather and almost constant enemy engagement, retreat would be slow and challenging.

As the 1st and 7th Marine Divisions commenced their retreat, the US Air Force proved vital in countering enemy attacks. A pivotal tool the Air Force used to cover their retreat was napalm. A highly flammable and explosive weapon made up of chemicals such as thermite, napalm ignited and burned at a temperature of 1,800 degrees Fahrenheit. In about 15 years’ time, napalm would be a key weapon throughout the Vietnam War. During the retreat from Chosin, napalm stifled enemy engagements into American lines and provided enough cover for them to continue their southward retreat. Yet these napalm drops also caused friendly fire casualties amidst the confusion and speed of retreat.

The emphasis on speed inevitably forced marines to leave many of their dead behind. As the wounded and a majority of the other surviving soldiers reached the rallying point at Hagaru-ri, the US Air Force once again came to the rescue by initiating air evacuations. Regardless of the losses, the gathering of soldiers around the reservoir into Hagaru was an important achievement. Separated friends reunited for a brief moment of celebration, which boosted morale. Meanwhile, the aforementioned airstrip was finally completed to the extent that it was possible to land C-47s. A total of 4,500 wounded would be flown out while the rest, another 15,000 men and 1,500 vehicles, continued southward through intervals of enemy fire and relentless freezing weather.

While on the road to Koto-ri, the speed of the 1st and 7th Marine Divisions would slow due to multiple obstacles. The enemy continued to impede their pace, but more problematic were the burnt-out shells of vehicles left behind from Task Force Drysdale’s earlier operation to Hagaru. To continue, these vehicles needed to be moved or maneuvered around under constant enemy fire. Further complications arose with the Chinese prisoners of war (POW) being held. At the commencement of the retreat, UNC forces held 147 POWs, but these prisoners would take any opportunity to escape. Many would die in the attempt, with only 13 remaining in the UNC’s hands. After 38 hours of marching and fighting, the Marines made it to Koto-ri, with 103 of their men killed and 506 wounded.

As Marines settled into Koto-ri on December 8th with their man-made foxholes, created with the help of C-3 demolition, more troubling news arrived. The last milestone into friendly territory was the Funchilin Pass, a bridge that had been blown up and reconstructed multiple times during the conflict. Once again, the bridge had been destroyed, and a solution urgently needed to be found. The Marines were exposed to enemy fire, and the weather continued to deplete what little strength they had. Lieutenant Colonel John Partridge, who oversaw the construction of the Hagaru airstrip, was tasked to build a new bridge in the Funchilin Pass.

The Marines in Koto-ri lacked the necessary materials to build the new bridge, and Colonel Partridge had to find a way to get them the supplies they needed. Given their position, the only possibility was to airdrop the bridge parts and hope that none of it shattered upon impact. Before attempting this, they conducted a rehearsal of the airdrop to confirm the bridge parts wouldn’t break. However, the trial failed. Yet, with time now running out, Colonel Partridge decided to deliver the materials immediately rather than spend precious time on a second trial run. Luckily, the bridge parts were delivered intact, and a bridge across the Funchilin Pass was constructed.

In the following days, a long line of soldiers and trucks retreated through the Funchilin Pass into friendly territory. On December 10th, the men continued southward until reaching their final destination at Port Hamnung, where US ships awaited them. For the next couple of weeks, the UNC forces would gather their supplies and evacuate the area. By December 24th, all UNC personnel had withdrawn, and the port was bombed by the US Navy.

The toll of the Chosin battle was staggering for both sides, especially for the Chinese. The total number of casualties from Chosin was 4,418 American casualties in battle and more than 7,000 to the cold. On the other side, 37,500 Chinese were either killed, wounded, or missing. While many died in combat, an equal or larger number of Chinese soldiers died from exposure and the freezing temperatures.

The Battle at the Chosin Reservoir was significant for three reasons. First, China’s military intervention changed the course of the conflict, preventing the DPRK’s near-certain defeat and prolonging the conflict by another two years. Consequently, General MacArthur was relieved of his command the following year.

Second, the battle demonstrated how domestic media coverage in America could influence its wars abroad and vice versa. This was a precursor to what would happen in the Vietnam War (1964-1973), when coverage would be amplified due to the introduction and proliferation of television sets.

Lastly, similar to the US soldiers of WWII, the 1st, 5th, and 7th US Marine Divisions, alongside the British Royal Marines, displayed immense courage and resilience against an overwhelming force. While the battle of the Chosin Reservoir was far from a military victory, it nonetheless stands as a defining moment in Marine Corps history.