Notwithstanding enemy warnings, in addition to disregarding significant intel of large-scale Chinese troops advancing toward the borders of North Korea, famed General Douglas MacArthur insisted on pushing through the reunification agenda of the Korean peninsula five months into the war.

Extremely confident of a decisive victory, MacArthur sent thousands of coalition forces composed of the Republic of Korea (ROK), the United States, and various United Nations units to press on deep into the snowcapped mountains of Pyongyang and into the Yalu river. This decision will soon blow up into one of the worst military intelligence blunders in military history, with thousands of combat and non-combat casualties as part of the repercussions.

Here’s a rundown of what happened during that harrowing 17-day action at Chosin Reservoir.


Three months in, the tide of the Korean war shifted in favor of the ROK and its UN allies following the arrival of the US X Corps at Incheon and the successful breakout of the Eighth Army from Pusan. At this point, the time of the North Korean People’s Army (NKPA) was trickling down into an obvious defeat, and MacArthur saw this as an opportunity to rapidly advance in hopes of entirely terminating the enemies, reunifying Korea, and ending the war by Thanksgiving.

Blinded by supreme confidence, MacArthur underestimated the strength and capabilities of the impending participation of the Chinese Communist Forces (CCF), as well as the latter’s hints of dispatching a large number of its “volunteer” troops to infiltrate the northeastern side of the peninsula.

Nevertheless, MacArthur and the rest of the American forces had a reason for confidence. After all, at this point, they all believed they had won the war.

battle of chosin documentary
Screengrab via PBS/YouTube

24 November 1950

Ignoring the concerning reports from the front, MacArthur ordered both the Eight Army and X Corps to push on to the Yalu on the 24th. Besides the mounting evidence that an increasing number of Chinese forces was on its way, US forces have also been struggling to combat the region’s biting Siberian cold, with temperatures dropping as low as -36° Fahrenheit.

Due to the extreme cold, weapons began to jam as tanks encountered various mechanical issues, while medical supplies gradually depleted to treat frostbite, which plagued the ranks—foreshadowing the looming tragedy.