UN Forces retreat from North Korea

UN retreat from North Korea
Part of the Korean War
Map of US Eighth Army retreat, 1–23 December 1950
Date 2–24 December 1950 Location North Korea Result Successful UN withdrawal UN completely withdraws from North Korean territory Territorial changes Chinese and North Korean forces retake all Korean territory north of 38th Parallel.
Belligerents
United Nations  United States  United Kingdom  Turkey  Australia  South Korea	North Korea  China
Commanders and leaders
Shin Sung-Mo	Choi Yong-kun Kim Chaek Kim Ung Kim Mu Chong Peng Dehuai
Units involved
Eighth Army I Corps 1st Cavalry Division 24th Infantry Division 1st Infantry Division 27th Commonwealth Brigade 29th Independent Infantry Brigade IX Corps 2nd Infantry Division 25th Infantry Division 1st Turkish Armed Forces Command Republic of Korea Army I Corps 3rd Infantry Division Capital Division II Corps 6th Infantry Division 7th Infantry Division 8th Infantry Division Fifth Air Force X Corps 1st Marine Division 3rd Infantry Division 7th Infantry Division 1st Marine Air Wing	Korean People's Army 1st Division 2nd Division 3rd Division 4th Division 6th Division 7th Division 8th Division 13th Division 15th Division 19th Division 27th Division 41st Division 43rd Division 17th Armored Division 105th Armored Division People's Volunteer Army 20th Army 58th Division 59th Division 60th Division 89th Division 26th Army 76th Division 77th Division 78th Division 88th Division 27th Army 79th Division 80th Division 81st Division 94th Division 38th Army 112th Division 113th Division 114th Division 39th Army 115th Division 116th Division 117th Division 40th Army 118th Division 119th Division 120th Division 42nd Army 124th Division 125th Division 126th Division 50th Army 148th Division 149th Division 150th Division 66th Army 196th Division 197th Division 198th Division
Strength
423,000[1]	~97,000[1]: 49  ~300,000[1]: 53–5

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The UN Forces retreat from North Korea was the withdrawal of

On 30 September Republic of Korea Army (ROK) forces crossed the 38th Parallel, the de facto border between North and South Korea on the east coast of the Korean peninsula and this was followed by a general UN offensive into North Korea to pursue the shattered North Korean Korean People's Army (KPA). Within one month UN forces were approaching the Yalu River prompting Chinese intervention in the war. Despite the initial attacks by the Chinese People's Volunteer Army (PVA) in late October-early November, the UN renewed their offensive on 24 November before it was abruptly halted by massive Chinese intervention in the Second Phase Offensive starting on 25 November. Following their defeat by the PVA at the Battle of the Ch'ongch'on River and tactical withdrawal at the Battle of Chosin Reservoir, UN forces evacuated North Korea in its entirety on 25 December. UN forces then prepared new defensive lines above Seoul for an expected renewal of the PVA offensive. The UN withdrawal from North Korea included many migrations of refugees fleeing from Chinese and North Korean forces that quickly recaptured North Korea. Two notable mass refugee escapes from North Korea include the Hungnam evacuation and the evacuation of Pyongyang.^[2]

Background

On the night of 28 November UN commander General

With almost no PVA contact, Walker's forces moved south of Pyongyang within twenty-four hours. Much of the city was on fire by 07:30 on 5 December when the rearguards destroyed the last bridges over the Taedong and set off final demolitions in the section of Pyongyang below the river. Colonel Stebbins, Walker's G-4 who supervised the removal of materiel from Chinnamp’o and Pyongyang, would have preferred a slower move by 72 or even 48 hours. Given that additional time, Stebbins believed, the service troops could have removed most of the 8–10,000 tons of supplies and equipment that now lay abandoned and broken up or burning inside Pyongyang. More time also could have prevented such oversights as leaving at least 15 operable M46 Patton tanks on flatcars in the railroad yards in the southwestern part of the city. Fifth Air Force planes struck these overlooked tanks on 6 December, but differing pilot claims left obscure the amount of damage done. Although Chinnamp’o was exposed after early morning of the 5th, evacuation of the port continued until evening without harassment from PVA forces. Pressed only by time and the wide range of the Yellow Sea tides, the port troops from 2 through 5 December loaded LSTs, transports of the Japanese merchant marine, a squadron of U.S. Navy troop and cargo transports, and at least a hundred Korean sailboats. Aboard these craft went casualties, prisoners, and materiel sent from Pyongyang; the supplies and equipment on the ground around the port; the port service units themselves; and some thirty thousand refugees (most of them on the sailboats). Four American destroyers took station off Chinnamp’o, and aircraft from the British carrier HMS Theseus appeared overhead on the 5th to protect the final outloading. That morning the port commander received word from Colonel Stebbins to get the last ships under way on the favorable tide at 17:00. The last three ships pulled away from the docks near that hour. Demolition crews set off their last explosives, and shortly afterward the last men ashore drove an amphibious truck out to a waiting ship. Some two thousand tons of supplies and a few items of port equipment had had to be destroyed for lack of time to remove them. The men and materiel sea-lifted from Chinnamp’o were landed either at

The trace of the new army position vaguely resembled a question mark. I and IX Corps defenses between Kyomip’o and Yul-li formed the upper arc, IX Corps positions on the east flank from Yul-li southeastward to Sin’gye shaped the shank, and clumps of army reserves below Sin’gye supplied several dots. The figure traced was appropriate since Walker now had been out of meaningful contact with PVA forces for five days, had no clear idea of the location or movement of the main PVA body, and could only speculate on what the PVA commander could or intended to do next.[1]^: 155

In an attempt to fill the intelligence gap deriving from the withdrawals and the PVA slowness to follow, Walker on the 5th ordered I Corps commander General

The apprehensions evident in Walker's appraisals and plans were apparent in Tokyo as well. General 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. The Joint Chiefs fully approved MacArthur's adoption of defensive tactics, but were not convinced that a successful static defense was impossible. They suggested that MacArthur place the Eighth Army in a continuous line across Korea between Pyongyang and Wonsan. MacArthur objected, claiming such a line was too long for the forces available and that the logistical problems posed by the high, road-poor mountains then separating Eighth Army and X Corps were too great. 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. In any event, he predicted, the Chinese already arrayed against the Eighth Army would compel it to take a series of steps to the rear. The Joint Chiefs of Staff disagreed that X Corps’ concentration at Hamhung would produce the effect MacArthur anticipated. In their judgment, the Chinese already had demonstrated a proficiency for moving strong forces through difficult mountains, and the concentration of the X Corps on the east coast combined with the predicted further withdrawals of the Eighth Army would only widen the opening through which the Chinese could move. They again urged MacArthur to consolidate Eighth Army and X Corps sufficiently to prevent large enemy forces from passing between the two commands or outflanking either of them. But MacArthur defended his view of a Pyongyang-Wonsan line, pointing out that he and Walker already had agreed that Pyongyang could not be held and that the Eighth Army probably would be forced south at least as far as Seoul. Turning his reasoning in support of a request for ground reinforcements "of the greatest magnitude," he emphasized on 3 December that his present strength would allow him at most to prolong his resistance to the PVA by making successive withdrawals or by taking up "beachhead bastion positions" and that a failure to receive reinforcements portended the eventual destruction of his command. The response to MacArthur's estimate was as gloomy as his predictions. 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. The remaining Joint Chiefs meanwhile replied from Washington that preservation of the UN Command was now the guiding consideration and that they concurred in the consolidation of MacArthur's forces into beachheads. Beachhead sites that in varying degrees could facilitate a withdrawal from Korea were Hungnam and Wonsan for X Corps and Inchon and Pusan for the Eighth Army. General Collins, while touring Korea between 4 and 6 December, heard General Walker and General Almond on the best beachheads and on how best to handle their respective commands. Almond believed that he could hold Hungnam indefinitely and wanted to stay there out of certainty that by doing so he could divert substantial Chinese strength from the Eighth Army front. Walker, on the other hand, believed the preservation of the Eighth Army required a deep withdrawal. Walker attempted to forestall any order to defend Seoul, insisting that tying his forces to the city would only allow the PVA to encircle Eighth Army and force a slow, costly evacuation through Inchon. He favored pulling back to Pusan, where once before he had broken the KPA offensive and where now, if reinforced by X Corps, Eighth Army might hold out indefinitely. MacArthur's G-3, General Wright, meanwhile recommended Pusan as the best beachhead for both the Eighth Army and X Corps on that grounds that should UN forces be compelled to leave Korea, they should leave the distinct impression of having delayed the enemy as long and as well as possible. Wright also pointed out that defending successive Lines into the southeastern tip of the peninsula would afford UN air forces the greatest opportunity to hurt the PVA; further, if a withdrawal from Korea became necessary during the remaining winter months, MacArthur's command could escape extreme weather conditions at Pusan; finally, an evacuation at any time could be effected faster through the Pusan facilities than through any other port. To permit the longest delaying action possible and to enable an evacuation from the best port, Wright recommended that X Corps be sea lifted from Hungnam as soon as possible and landed in southeastern Korea, that X Corps then join the Eighth Army and pass to Walker's command, and thereafter that the UN Command withdraw through successive positions, if necessary to the Pusan area.^{[1]: 157–9}

On 7 December in Tokyo, Generals MacArthur, Collins and

On 7 December General 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. So guided, Walker on the 8th laid out Line B, which duplicated Line A eastward from Hwach’on but in the opposite direction fell off to the southwest to trace the lower bank of the Imjin and Han Rivers, some 20 miles (32 km) behind the Yesong River. This line was at least 20 miles (32 km) shorter than Line A and matched the northernmost coast-to-coast line designated by MacArthur, and now became the line toward which Walker began to move his forces for the defense of Seoul.^[1]: 160

On 11 December MacArthur made his first visit to Korea since he had watched the start of the Home by Christmas Offensive on 24 November. He was now on the peninsula for a firsthand view of the Eighth Army and X Corps after their setbacks at the hands of the PVA and for personal conferences with Walker and Almond on the steps the two line commanders had taken or planned to take in carrying out the maneuvers and command change he had ordered three days before. When MacArthur reached Walker's headquarters (having first stopped in northeastern Korea to confer with General Almond), he was able to see not only the Eighth Army plan for withdrawing to Line B but also Walker's plans in case the Eighth Army again was squeezed into the southeastern corner of the peninsula. Reviving an unused plan developed by the Eighth Army staff in September, Walker reestablished not only the Naktong River defenses but also three lines between the old perimeter and Pusan, each arching between the south coast and east coast around the port. Nearer Pusan, the Davidson Line curved northeastward 68 miles (109 km) from a south coast anchor at

To General MacArthur, the elaborate preparations for a withdrawal below Seoul indicated that Walker had decided against a determined defense of the city. When MacArthur raised the question, Walker assured him that he would hold Seoul as long as he could. But, Walker pointed out, sudden collapses of ROK forces twice before had placed the Eighth Army in jeopardy. Nor had the ROK shown any increased stability even after strenuous efforts to improve it. 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. In Walker's mind these two dangers, of another sudden ROK collapse and of making a river crossing in a withdrawal, made his extensive preparations a matter of "reasonable prudence." Walker also was convinced that the PVA/KPA were now capable of opening an offensive at any time. 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. Between 8 and 14 December Walker caught a southeastward shift of the KPA II Corps, the bulk of which previously had been concentrated in and operating as a guerrilla force out of the mountains between Koksan and Inchon. Apparently having retaken regular status, the Corps paralleled the Eighth Army's southeastern withdrawals below Pyongyang. 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. It also seemed that earlier reports of reconstituted KPA units joining the II Corps were correct. Several renewed KPA divisions apparently had assembled immediately behind the II Corps to make a total strength of 65,000 plausible for the KPA troops directly opposite the Eighth Army's central sector as of 23 December.^{[1]: 163–4}

As late as 17 December Walker was still completely out of contact with PVA forces and by the 23rd had encountered only a few, these in the I and IX Corps sectors in the west. General Partridge, who had shifted the emphasis of Fifth Air Force operations to armed reconnaissance and interdiction about the time Walker had given up Pyongyang, was able to verify that PVA forces had moved south in strength from the Ch'ongch'on battlefields, but not how far. 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. But then, to escape Partridge's punishing attacks, the PVA reverted to their strict practices of concealment and camouflage and halted virtually all daytime movement. Walker, consequently, had no clear evidence that the main body of the PVA XIII Army Group had moved any farther south than Pyongyang. But on the basis of repeated reports from agents and air observers that PVA troops and supplies were moving southeastward from Pyongyang, by the 23rd he considered it possible that three or four Chinese armies with about 150,000 troops were bunched within a day's march of the Eighth Army's central front. This possibility brought the estimate of enemy strength above Walker's central positions to 180,000. Furthermore, Walker judged, these troops could be reinforced by any units of the PVA XIII Army Group remaining in the Pyongyang area within four to eight days and by the PVA/KPA units currently operating in the X Corps sector within six to ten days.^{[1]: 164–5}

To Walker, the apparent concentration and disposition of PVA/KPA forces opposite his central front clearly suggested offensive preparations in which KPA II Corps was screening the assembly of assault forces and supplies. Small KPA attacks below Yonch’on and from Hwach’on toward Ch’unch’on seemed designed to search out weaknesses in the Eighth Army line in those areas and indicated the possibility of a converging attack on Seoul south along Route 33 and southwest over the road from Ch’unch’on. A likely date for opening such an attack, because of a possible psychological advantage to the attackers, was Christmas Day. Walker's largest hope of holding Seoul for any length of time in these circumstances rested on the arrival of the remainder of X Corps from northeastern Korea. Once he had General Almond's forces in hand, Walker planned to insert them in the Ch’unch’on sector now held by the untried ROK III Corps. This move would place American units along the Ch’unch’on-Seoul axis, one of the more likely PVA/KPA approaches in an attack to seize Seoul. 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 General Almond to get his forces out of northeastern Korea and to refurbish them for employment under the Eighth Army.^[1]: 165

Withdrawal of X Corps from northeast Korea

Following the earlier decision to concentrate X Corps forces at Hungnam, the evacuation of Wonsan had begun on 3 December. In a week's time, without interference from PVA/KPA forces, the US 3rd Infantry Division task force and a Marine Corps shore party group totaling some 3,800 troops loaded themselves, 1,100 vehicles, 10,000 tons of other cargo, and 7,000 refugees aboard transport ships and

In announcing the completion of X Corps’ withdrawal from Hungnam in a communique on 26 December, General 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. He blamed the incorrect assessment of Chinese strength, movements, and intentions before the resumption on the failure of "political intelligence... to penetrate the iron curtain" and on the limitations placed on field intelligence activities, in particular his not being allowed to conduct aerial reconnaissance beyond the borders of Korea. So handicapped, his advance, which he later termed a "reconnaissance-in-force," was the "proper, indeed the sole, expedient," and "was the final test of Chinese intentions." In both the advance and the redeployment south, he concluded, "no command ever fought more gallantly or efficiently under unparalleled conditions of restraint and handicap, and no command could have acquitted itself to better advantage under prescribed missions and delimitations involving unprecedented risk and jeopardy. But while MacArthur earlier had proclaimed that only by advancing could he determine PVA/KPA strength, he had not designed or designated the UN attack as a reconnaissance in force, nor was it. It was, rather, a general offensive whose objective was the northern border of Korea.[1]^: 175–6

Ridgway takes command

On the morning of 23 December General Walker left Seoul by jeep to visit units above

On reaching the main Eighth Army headquarters at Taegu late on 26 December, Ridgway was displeased at finding the bulk of his staff so far to the rear. His immediate step was to get to the army forward command post. At dawn on 27 December he flew to Seoul, where the handful of staff officers he found deepened his resolve to remedy the headquarters arrangement. He planned not only to redistribute his staff but also to move the forward command post to a more central location from where he could reach all Corps and divisions in minimum time. Following a staff conference and meetings with American Ambassador John J. Muccio and South Korean President Syngman Rhee in Seoul, Ridgway began a four-day reconnaissance of the Line B front that took him to all Corps and divisions except the ROK Capital Division on the east coast, whose sector was quiet and unthreatened by impending PVA/KPA action. By evening of the 30th he was back at Eighth Army headquarters in Taegu, much disturbed by what he had learned. The Eighth Army was clearly a dispirited command. "I could sense it the moment I came into a command post... I could read it in the faces of... leaders, from sergeants right on up to the top. They were unresponsive, reluctant to talk. I had to drag information out of them. There was a complete absence of that alertness, that aggressiveness, that you find in troops whose spirit is high." The attack that Ridgway had hoped would be possible he now considered plainly out of the question. He also considered it imperative to strengthen the Eighth Army front if his forces were to hold Line B. Whether he had time enough to do so was questionable. Additional evidence of an imminent PVA/KPA offensive had appeared as Ridgway reconnoitered the front, and the coming New Year holiday was now a logical date on which to expect the opening assault.^{[1]: 179–80}

UN forces on the eve of the Chinese third phase campaign

Unit dispositions along the line had changed little since General Walker succeeded in manning it. The

Holding against the threatening enemy offensive, Ridgway judged, rested on committing most of his reserves early and on revitalizing the spirit of the Eighth Army. By the time he returned to Taegu on the 30th he had taken several steps toward achieving both. Restoring the Eighth Army's morale and confidence, Ridgway believed, depended mainly on improving leadership throughout his command, but before he would relieve any commander, he wanted personally to see more of the man in action, to know that the relief would not damage the unit involved, and to be sure that he had a better commander available. For the time being, he intended to correct deficiencies by working "on and through" his current Corps and division commanders. One deficiency he had noted was that many commanders conducted operations from command posts far behind the front. To correct this practice, he ordered "division commanders to be up with their forward battalions, and... corps commanders up with the regiment that was in the hottest action." He saw further weaknesses in leadership and staff work in the intelligence briefings he received. Confronted during one of the first briefings with a map whose main feature was "a big red goose egg... with ‘174,000’ scrawled in the middle of it," Ridgway said "Here the enemy was leaning right up against us, but we did not know his strength, and we did not have his location pinpointed." He attributed such imprecision directly to the Eighth Army's tendency to "look over its shoulder." As a result of this tendency, the line troops had not maintained proper contact with enemy forces or learned enough about the terrain to their front. He promptly rebuked his subordinates for failing to meet these two basic combat requirements. They were to patrol until they had defined the enemy's positions and determined the strengths of units opposite them, and he warned that he "didn’t want to ask any man where a trail went and have him tell me he didn’t know." Ridgway did receive another intelligence report from Eight Army intelligence officer Colonel Tarkenton of the estimated strength of the Chinese XIII Army Group. The group's six armies, each with a strength of 29,000, were either along the Eighth Army front or in the immediate PVA/KPA rear area. Tarkenton believed KPA corps totaling 65,800 men also were at the front and that a fourth was approaching it. The greatest enemy strength seemed to be massed opposite the Eighth Army's west-central sector, an indication that the main attack would come through the Wonsan-Seoul corridor over Routes 33 and 3. A strong secondary attack farther east also seemed probable, either southwest over the Ch’unch’on-Seoul axis or south through Ch’unch’on and Wonju via Route 29, in an attempt to outflank I and IX Corps above Seoul. Two recent attacks by units of the KPA II and V Corps opened as Ridgway reached Korea, supported Tarkenton's prediction of a strong secondary effort in the east. 14 miles (23 km) northeast of Ch’unch’on, two KPA regiments coming from the Hwach’on Reservoir area hit the ROK 8th Division at the right of ROK III Corps and gouged 1 mile (1.6 km) deep salient before the ROK contained the attack. Out of the Inje area, 25 miles (40 km) northeast of Ch’unch’on, a larger force believed to include a division and a reinforced regiment struck southwestward through the ROK 9th Division's flimsy position at the left of ROK I Corps. 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. By extending these gains, especially the deeper southwestward thrust out of the Inje area, KPA forces conceivably could sever the Eighth Army's main lines of communication.^{[1]: 183–4}

Ridgway's first tactical move was to counter this threat from the northeast. On 27 December Ridgway ordered part of the 2nd Infantry Division north from Ch’ungju into the projected path of the KPA. General McClure was to move a regimental combat team 25 miles (40 km) north to Wonju, from where it could oppose any KPA attempt to advance south over Route 29 or west along Route 20 and where it could protect a vulnerable link of the central Pusan-Seoul rail line, which served as an Eighth Army supply route. McClure was in the process of moving the 23rd Infantry Regiment and the French battalion to Wonju on the 29th when the KPA attack out of Inje carried behind ROK II Corps farther north. Ridgway consequently ordered McClure to move the remainder of his division to Wonju and to send one regiment 25 miles (40 km) north of that town to Hongch’on where Route 29 from Ch’unch’on and Route 24 from the northeast intersected. McClure complied on the 30th, sending the 23rd Infantry toward Hongch’on to join the ROK 23rd Regiment, 7th Division. Before the 23rd Infantry Regiment could complete its move above Wonju, the KPA force reported by ROK III Corps to number between 700 and 1200 men, blocked Route 29 6 miles (9.7 km) below Hongch’on. The 23rd's advance became a clearing operation, made in concert with a battalion of the ROK 23d Regiment, which moved south out of Hongch’on and with the reserve ROK 5th Regiment, 3rd Division, which dropped south from Ch’unch’on to a point west of the KPA position and then struck eastward against it. The concerted effort cleaned out most of the roadblock on the 31st. The battalion of the ROK 23rd Regiment returned to Hongch’on while the ROK 5th Regiment and the leading battalion of the 23rd Infantry stayed to clear the remainder of the KPA position. The balance of the 23rd Infantry was strung out on Route 29, a battalion at Hoengseong 9 miles (14 km) below the roadblock site, the remainder still in Wonju where the rest of the 2nd Infantry Division was now assembling.^{[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. Against this possibility, Ridgway planned to reinforce this portion of the front, much as General Walker had decided earlier, by setting X Corps in the Ch’unch’on sector now held by ROK III Corps and by placing the bulk of his ROK forces along a narrower, more solid front in the highermountains and coastal slopes to the east. Since time was critical, Ridgway on 28 December pressed General Almond and the commander of the 2nd Logistical Command, General Garvin, to quicken the readiness preparations of the 1st Marine, 3rd and 7th Divisions. The Marines, now reattached to X Corps, and the 7th Division were fully assembled but were still refurbishing and the 3rd Division, last to leave Hungnam, was not yet three-quarters ashore. The ships carrying the remaining 3rd Division troops were in Pusan harbor, however, and following Ridgway's 29 December order that these ships be unloaded without delay, the balance of the 3rd Division was ashore and en route to the division's assembly area south of Kyongju by nightfall on 30 December. 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. Under these plans X Corps headquarters and whichever of Almond's present divisions completed its preparations first would move to Wonju, where Almond would add the US 2nd Infantry Division and possibly one ROK division to his command as substitutes for the two divisions left behind. Even this arrangement would take time; the estimate for moving one of Almond's current divisions from its southern assembly area to the battle zone was 8 to 10 days. Once forward, X Corps was to operate with the initial mission of destroying any PVA/KPA penetration of the ROK front above it and of protecting IX Corps’ east flank. Ridgway gave Almond detailed instructions on the 30th. Having learned that the 7th Division would be ready ahead of the other two divisions, he directed Almond to move one of its regiments the next day to Chech’on, 20 miles (32 km) below Wonju, where Route 60 and a mountain road coming from the east and northeast joined Route 29. When Almond could get the remainder of the division forward, he was to assemble the 7th near the 2nd so that both divisions could be deployed quickly against any PVA/KPA penetration from the direction of Ch’unch’on and Inje or from the east toward Hoengsong and Wonju. Almond subsequently could expect to occupy a sector of the front. In the meantime, he was to develop Route 29 southeastward from Wonju through Chech’on, Tanyang, Yongju and Andong as the main X Corps supply route.^{[1]: 185–6}

On 31 December Ridgway placed the 1st Marine and 3rd Divisions in army reserve. When fully refurbished, the Marines were to move from Masan to an east coast assembly in the Yongch’on-Kyongju-P’ohangdong area and prepare to occupy blocking positions wherever needed to the north. The 3rd Division was to reassemble in the west. As soon as General Soule finished reorganizing and reequipping his forces he was to move them into the Pyongtaek-Ansong area 40 miles (64 km) south of Seoul and prepare them for operations in either the I or IX Corps sector.^[1]: 186

The Seoul defenses

While reinforcing the ROK sector of the front, Ridgway also deepened the defense of Seoul. After conferences with General Milburn and General Coulter on the 27th, he instructed them to organize a bridgehead above Seoul along a line curving from the north bank of the Han west of Seoul through a point just below Uijongbu at the junction of Routes 33 and 3 to the north and back to the Han east of the city. The Bridgehead Line would be deep enough to keep the Han bridges below Seoul free of PVA/KPA artillery fire. The position therefore would be suitable for covering a general withdrawal below Seoul that might accompany or follow the occupation of the Bridgehead Line. Milburn and Coulter each were to place a division on the Bridgehead Line if the expected PVA/KPA attack forced them to vacate their Line B positions. Ridgway at first restricted any I and IX Corps withdrawal from the present front to his own personal order. But on reconsidering the high estimate of PVA strength opposite the two Corps, the tendency of some ROK units to break under pressure, and the demonstrated PVA preference for night attacks, he realized that this restriction could create a costly delay should Milburn and Coulter be unable to contact him promptly. He therefore authorized the two Corps commanders to withdraw on their own at any time they agreed that it was necessary but could not reach him. No matter who gave the order, Ridgway insisted that a withdrawal to the Bridgehead Line be more than a mere move from one line to another; both Corps were to attack PVA/KPA forces who followed. The terrain could accommodate this tactic, especially in the Wonsan-Seoul corridor where the PVA/KPA would be obliged to use routes surrounded by higher ground. Ridgway expected Milburn and Coulter to leave strong forces of infantry and armor posted in this high ground as the two Corps withdrew; these forces would strike advancing PVA/KPA units and disrupt the follow-up before they themselves moved back to the bridgehead.^{[1]: 186–7}

Ridgway attached the 2nd Ranger Company to the 1st Cavalry Division in the west and the 4th Ranger Company to the 7th Division in the east. 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. Anticipating an opening PVA/KPA attack towards the capital on New Year's Day, Ridgway returned there on the afternoon of 31 December. According to Colonel Tarkenton's latest intelligence estimate, PVA/KPA forces were fully deployed. In the west, KPA I Corps straddled Route 1 at the Imjin with the PVA

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. His request was strongly rejected by Truman.[3]^[4]

References