X Corps landed behind the North Korean lines at Inchon on September 15, 1950. Within two weeks, the North Korean army was largely destroyed or made ineffective. Of the 70,000 NK who had been attacking UN forces at the Pusan perimeter, only about 30,000 made it back to North Korea, mostly over roads on the east coast which our generals neglected to block. The way to the Yalu, and total destruction of North Korea's military power, seemed virtually unopposed.
Indeed, the ROK 3rd division attacked across the 38th parallel up the east coast on September 30, with the ROK 6th division crossing to attack the Iron Triangle of Chorwon, Kumwha and Pyonggang on October 6, and Eighth Army crossing near Kaesong on October 8. October 10 Wonson, and October 19 Pyongyang, had fallen. ROK units had reached Chosan on the Yalu river, the border between North Korea and China's Manchuria.
The 1st Marine Division had been withdrawn from the Seoul area, and sailed around the peninsula. 3,000 mines had been laid in the muddy, shallow environs of Wonsan, which took two weeks to clear before the division could land. They spent that time circling around off-shore losing, for a time, the finely honed physical condition they had won in the battles around Seoul. October 26, they landed, apparently into a safe and secure world, on the same day elements of the ROK II Corps reached the Yalu. The war seemed almost over.
But, it was actually only starting.
October 25, Chinese Communist Forces (CCF) struck China's first blow in support of the KPA. Units of the CCF 39th army destroyed a battalion of the ROK 6th division near Onjong. The CCF infiltrated past the ROKs, set up road-blocks behind them, and brought them under enfilading fire. The ROKs panicked and fled any way they could (one indication of how little they actually fought before running, over 2700 of their 3100 men escaped to the Chongchon). Next day a single battalion, the CCF 373/125, foot infantry with only mortar support, routed the entire mechanized 7th regiment of the ROK 6th division, capturing all their vehicles and artillery. Here, KMAG advisors and many of the ROKs stayed in their positions and fought to the end. Only 875 men survived of the 3,552 in the regiment, with all American advisors being killed in place except one, who was captured after being wounded in 15 places. By October 30, the ROK 6th division was finished.
By November 2, the US 1st Cav's 8th Cavalry Regiment had lost half its strength and most of its vehicles and equipment, as well. When all stragglers returned, over 800 men of the Regiment had been lost.
To the wild sound of Chinese bugles and the shrilling of whistles (which actually was the only communications available to the CCF below the regiment level), the entire Eighth Army had been driven back to the Chongchon by the CCF 39th Army, consisting of only 3 divisions, a total of about 30,000 foot-infantry, supported only by 70mm howitzers, mortars, and a few Katyusha rockets. (A month later, attacking only one single American Marine division, but a resolute division that was well led, it would take over 3 times as many CCF to force a retreat. Moreover, the 10 CCF divisions would be so badly hurt while pushing back 1st Mar Div that they would never go into combat again.)
In the east, 1st Mar Div's 7th Marines were sent to relieve the ROK 26th Regiment at Sudong-ni, and found themselves fighting the CCF 124th division. Unlike the 26th, and our Eighth Army in the west, the 7th Marines won in a vicious fight. Because of the mountainous terrain, the 124th had left their artillery behind them and joined the battle supported by nothing heavier than 82mm mortars. The Marines not only fought and defeated them as individual units, they used the full coordinated artillery and air support of an American infantry regiment with maximum effect. The 7th Marines essentially destroyed the CCF 124th as a fighting unit.
On 10 November, the Marines entered Koto-ri.
The CCF 39th which routed Eighth Army was just part of Lin Piao's Fourth Field Army; a force 600,000 strong, an army which had fought from Manchuria to Hainan Island in China's civil war, without losing one major battle. During the last half of October Piao's XIIIth Army Group, six armies, each of 3-10,000 man Infantry divisions, had crossed the Yalu undetected, at Sinuiju and Manpojin. 180,000 veteran troops were positioned to attack Eighth Army, and more were coming.
X Corps had captured prisoners from the CCF 89th, part of an entirely new force, the Third Field Army, believed by Far East Command to be stationed in Shanghai.
But ... Far East Command, without air intelligence of the CCF strength, with ground patrols seeing only the light screening forces CCF tactics placed ahead of their main armies, estimated CCF strength at 70,000 total. FEAC believed even this small estimate was composed of Chinese "Volunteers".
High Command simply refused to accept that China had entered the war, and was doing so in great force.
Instead of preparing interlocking defensive positions, in depth, and securing its flanks with reliable troops, instead of ensuring that its forces on the two coasts were capable of meeting any assault the Chinese were known to be capable of, Far East Command decided to address only the force they thought the Chinese were willing to commit. That's the difference between a bold stroke, and a gamble.
General Walker's Eighth Army was ordered to prepare for a final offensive to end the war. About 200,000 CCF were moving to meet them.
In the east, instead of concentrating on interlocking defenses around Hamhung, and Wonsan, X Corps was divided. 1st Marine Division was ordered further into the wild, isolated, wintery northern Taebaek mountains of the Chosin Reservoir. The 1st was to link with Eighth Army, and then race on to the Yalu. 7th Infantry Division was sent on a parallel course, further north and east.
But the CCF IXth Army Group, 3 Field Armies with 12 infantry divisions, a total of about 120,000 veteran troops, were moving to meet them.
Far East High Command believed they were sending our armies to finish a mop-up operation and put a final end to North Korea's military threat. In fact, they were sending unprepared troops into conflict with a large, veteran army of determined fighting men.
Our troops, accustomed to the mechanized and strong-point positions of Western wars, were being sent into savage conflict of a totally different kind. Into a massive infantry war, against a combat-hardened enemy which would employ flexible guerilla tactics, in the dead of an arctic winter.
Personally, I have always thought that the two weeks the Marines spent circling off Wonsan while we cleared the mines blocking their landing, may have saved the 1st Division. Possibly all of X Corps. With the 1st ashore earlier X Corps commander, aggressive army General Almond, would surely have extended X Corps into the Taebaek earlier. And further.
Whatever. The troops were definitely not going to make it home by Christmas.
