The U.S. military has had some horrific battles in its time. On this Memorial Day, as we remember our war dead, as opposed to Veterans Day when we recall those who served, it is instructive to recount perhaps the toughest battle American forces ever had to face.

There are many contenders for this bloody honor. Bunker Hill, Shiloh, Antietam, Kaserine Pass, the Bulge, Tarawa, Pusan, Ia Drang Valley, all have a claim. But for sheer brutality of weather, for the odds, and for the courage and determination of America and its allies nothing, for this analyst, comes close to the Chosin Reservoir.

It occurred during the Korean War. In June of 1950 the communist North of Korea, with Chinese communists and Soviet backing, invaded the U.S. allied South. They advanced and we were quickly pushed back to a small area in the southeast named by history The Pusan Perimeter. President Truman responded in force and the United Nations, in the best action of its entire existence, joined in the fight against the common enemy. But while we were being held at Pusan and barely holding on, U.S. General of the Army Douglas MacArthur was planning an end-around run by an amphibious invasion on the central west coast at Inchon.

The U.S. landing at Inchon was a great success. It cut off the Norks from their supply line and routed them all the way north much past the border between North and South Korea. In fact, U.S. and U.N. forces even took the Nork capitol of Pyongyang. General MacArthur should have stopped there, as he was getting ominously close to the Yalu River and China. The Chinese, through diplomatic channels, warned the U.S. and U.N. not to get too close to the border. But MacArthur, wanting the glory and laurels of a total victory, chose to ignore them.

Thus, as we probed the area around the Chinese border, on November 27, 1950 the Chicoms struck with 120,000 troops in the area of the Chosin Reservoir. We had about 30,000 troops in the vicinity made up of elements of South Korean forces, British forces, the 1st Marine Division, the U.S Army 3rd Division, and the U.S. Army 7th Division. Our troops were commanded on the ground by General Oliver Smith. The Chinese troops were commanded by General Song Shilun.

To make a very long story shorter, Mao Zedong had ordered Shilun to completely destroy the U.N. forces. MacArthur and Smith, realizing their position, decided on a fighting withdrawal to the port of Hungnam and evacuation of our forces by ship. The story of the clash is the battle at the reservoir and of the fighting on the road to Hungnam.

Encircled, outgunned, and outnumbered, U.S. and U.N. forces started to Hungnam under fire from every possible direction. The reservoir itself was frozen and thus fighting, some of it hand to hand, took place on what was essentially a frozen lake. It was like the devil’s skating rink.

The temperature was so cold vehicles stalled, guns jammed, frostbite was everywhere, but still we fought on and no matter how many we stopped, the Chinese kept coming in wave after human wave. Sometimes unarmed, often after whole units being mown down by U.S. troops, the Chinese would not relent. But the U.S. Army and Marines did not quit, they did not waver. When asked by the press (even then the press was annoying) why he was retreating after such a season of victories, General Smith said, “Retreat, hell! We’re not retreating, we’re just advancing in a different direction.” The line became legend.

In a long convoy, harassed by Chinese fire at every turn, we made it to Hungnam and left on Christmas Eve. After we boarded ships we blew up the port. The Chinese got there, to a view of useless rubble, on Christmas Day 1950. Outnumbered four to one, hand to hand combat on a frozen lake in the dead of winter. Now you can see why the Battle of the Chosin Reservoir is the toughest battle in American military history in terms of conditions and odds, and one of the best in terms of American courage and grit.