[1]: 103–4 Following their victory in the Battle of the Ch'ongch'on River, the PVA did not pursue the US Eighth Army's 20 miles (32 km) withdrawal from the Ch’ongch’on to the Sukch’on-Sunch’on-Songch’on line.

Walker moved the damaged US 2nd Infantry Division from Chunghwa into army reserve at Munsan-ni on the Imjin River 22 miles (35 km) north of Seoul, where General Laurence B. Keiser, with priority on replacements, was to rebuild his unit.

On 2 December, after General Yazıcı had recovered some 3500 of his original 5000 men, Walker ordered the brigade to Kaesong, 15 miles (24 km) north of Munsan-ni, to complete refurbishing under Keiser's supervision as more of its members were located and returned.

But now Walker's forces were about to give up the locale of the Eighth Army's main forward stockpiles, and although the smaller stores at Chinnamp’o might be evacuated, it was less likely that the larger quantities brought into Pyongyang over the past several weeks could be completely removed on such short notice.

Agents on the same day verified the presence of PVA troops in Pyongyang and reported that KPA regulars were joining North Korean guerrillas to the east and right rear of the Eighth Army.

Because his forces at no time since 30 November had captured or even sighted a PVA soldier during the sporadic encounters along the army right, he was beginning to believe that all enemy troops immediately east of him were KPA.

As a preliminary, Walker obtained MacArthur's agreement to erase the southern segment of the Eighth Army-X Corps boundary so the peninsula below the 39th Parallel, more generally south of a line between Pyongyang and Wonsan.

He chose coast-to-coast positions running from the mouth of the Yesong River, almost 40 miles (64 km) behind Haeju, northeastward through Sibyon-ni, southeast through Ch'orwon and Hwach'on, then eastward to Yangyang on the Sea of Japan.

MacArthur, although his main intention may have been to coax reinforcement, already had notified the Joint Chiefs of Staff that the UN Command was too weak to make a successful stand when he informed them on 28 November that he was passing to the defensive.

By concentrating the X Corps in the Hamhung area, MacArthur countered, he was creating a "geographic threat" to enemy lines of communication that made it tactically unsound for PVA forces to move south through the opening between those units.

Prompted by earlier dismal reports to visit the Far East for a firsthand appraisal, Army Chief of Staff General J. Lawton Collins informed MacArthur on 4 December that no reinforcement in strength, at least in the near future, was possible.

Earlier pessimistic reports to Washington notwithstanding, MacArthur apparently believed that the Eighth Army and X Corps combined could man this line; indeed, he expected Walker to make an ardent effort to hold it.

Truman issued instructions on 5 December by which he intended to insure that information made public by an executive branch official was "accurate and fully in accord with the policies of the United States Government."

[1]: 159–60 On 7 December MacArthur had radioed a warning to both Walker and Almond of the next day's order for successive withdrawals, the defense of Seoul short of becoming entrapped, and the assignment of X Corps to the Eighth Army.

By 20 December ROK I Corps had been sea lifted in increments out of northeastern Korea, landed at Pusan and near Samch’ok close to the east coast anchor of Line B, and transferred to Eighth Army control.

He already had directed the removal of major supply stores located in or above Seoul to safer positions below the Han River and had ordered the reduction of stocks held in the Inchon port complex.

If, as he suspected, the ROK units now along the eastern two-thirds of Line B failed to stand against an attack, his positions north of Seoul could not be held and the then necessary withdrawal would have to be made over an obstacle, the Han River.

He still had no solid contact with PVA/KPA forces, but by pressing intelligence sources over the previous two weeks he had obtained sufficient evidence to predict an imminent attack and to forecast the strength, paths, objective, and even possible date of the next blow.

As Walker's forces spread out along Line B, the KPA Corps followed suit, occupying positions just above the 38th Parallel in the central sector, principally between Yonch’on in the Wonsan-Seoul corridor and Hwach’on, due north of Ch’unch’on.

Until mid-December his fighter pilots and light bomber crews discovered and attacked large troop columns moving openly in daylight over main and secondary roads between the Ch’ongch’on and Pyongyang.

Whether X Corps would be available soon enough depended first on how closely Walker had estimated the opening date of the threatening PVA/KPA offensive and second on how long it would take Almond to get his forces out of northeastern Korea and to refurbish them for employment under the Eighth Army.

[1]: 169–75 In announcing the completion of X Corps’ withdrawal from Hungnam in a communique on 26 December, MacArthur took occasion to appraise UN operations from the time his command had resumed its advance on 24 November and, once again, to remark on the restrictions that had been placed on him.

A battlefield success of any substance in the meantime would help Washington answer what MacArthur called the "mission vacuum," meaning the question raised by the Chinese intervention of whether UNC forces could or should stay in Korea.

Entering the rear area of the narrow ROK II Corps' sector, the attack force by 30 December established a strong roadblock on the central arterial, Route 29, almost 25 miles (40 km) below Ch’unch’on.

Before the 23rd Infantry Regiment could complete its move above Wonju, the KPA force reported by ROK III Corps to number between 700 and 1,200 men, blocked Route 29 6 miles (9.7 km) below Hongch’on.

[1]: 184–5 While installing the 2nd Division in the Hongch’on-Wonju area might hold off the KPA currently advancing from the northeast, the defensive weakness in the three ROK Corps sectors left open the likelihood of stronger, more effective PVA/KPA penetrations.

Since it was nevertheless obvious that X Corps as currently constituted could not move forward for some time, Ridgway on the 29th approved plans developed by his staff for adjusting Almond's order of battle to permit earlier commitment.

Since the 2nd Infantry Division was operating in the Wonju area where the surrounding mountains prohibited armor, he ordered McClure's 72nd Tank Battalion to the west for attachment to IX Corps, which might use it to punish any PVA/KPA advance on Seoul.

In addition, PVA/KPA artillery positions sighted from the air disclosed a large number of guns generally astride an extension of the I and IX Corps boundary, all well disposed to support an attack through the Wonsan-Seoul corridor.

[1]: 188 In the aftermath of the withdrawal, MacArthur created a list of "retardation targets" in Korea, Manchuria and other parts of China and requested 34 atomic bombs from Washington with the purpose of sowing a belt of radioactive cobalt to prevent any further Chinese advances.