UN units the ROK I Corps, the U.S. 17th Infantry Regiment, and other elements at the Yalu-might be cut off by the weight of the Chinese offensive, the X Corps was forced to withdraw these elements. Troops at the reservoir were also ordered to fall back. MacArthur then ordered Almond to concentrate the X Corps in the HamhungHungnam area; and early in December directed the Corps to withdraw to South Korea by a waterborne evacuation.

Most of the Corps reached the port of Hungnam without serious incident. However, some 14,000 men of the 1st Marine and 7th Infantry Divisions were trapped in the Hagaru-Kot'o area and were forced to fight their way to the coast along a narrow escape route. As the main column progressed along the road, a provisional battalion of marines and soldiers, aided by close and efficient air support, cleared the Chinese Communist forces from the high ground which dominated the road. Almond sent Task Force Dog, a reinforced battalion of the 3d Division, forward to Chinhung to relieve the Marine battalion there and to assist the withdrawal by providing support and rear guard action. Air Force, Navy, and Marine cargo planes parachuted daily airdrops of ammunition, food, and medicines to the column, and evacuated battle casualties. Fighter elements bombed and strafed the enemy-held mountainsides and Communist troop concentrations. On 9 December 1950 the two forces met in the mountains a few miles south of Kot'o and both moved toward Hamhung to be evacuated.

The water movement of the X Corps from North Korea required 173 vessels. About 350,000 measurement tons of cargo, including 17,500 vehicles, were salvaged; some 105,000 troops and more than 98,000 civilians were evacuated from Hungnam, Songjin, and Wonsan. Evacuation began on 11 December and was completed on 24 December, despite constant enemy fire and observation.

Situation at the Close of 1950. The Hungnam evacuation left North Korea once again controlled by Communist forces. Before the enemy renewed his attacks, General Walker was killed in an auto accident north of Seoul (23

December 1950). On 26 December Lt. Gen. Matthew B. Ridgway succeeded him in command of the Eighth Army in Korea.

On 30 December MacArthur warned the U.S. Joint Chiefs of Staff that the Chinese Communist forces could drive the U.N. forces out of Korea if they so desired. The United States, although anxious to avoid a full-scale war in Korea, was also determined to resist the Chinese-North Korean aggressors. Therefore the Joint Chiefs ordered MacArthur to defend his positions; to retire, if forced to, through a series of defensive positions as far back as the former Pusan Perimeter Line; to inflict as much damage as possible on the enemy; and to maintain his units intact. If necessary to avoid severe losses, he was authorized to withdraw to Japan.

Within this framework of operations, MacArthur invested General Ridgway with complete authority to plan and execute operations in Korea, and ceased the close supervision which he had formerly exercised over the Eighth Army and the X Corps. The latter, which had heretofore been a separate command, was assigned to the Eighth Army, thus placing all U.N. ground forces under that army's control. By this time fifteen nations of the U.N. had troops in Korea-the United States, Great Britain, Australia, Canada, New Zealand, India, South Africa, France, Greece, the Netherlands, the Philippines, Thailand, Turkey, Belgium, and Sweden. As 1951 began, U.N. ground forces numbered about 495,000, of which 270,000 were ROK troops. The U.N. Command estimated that the enemy had about 486,000 men, 21 Chinese and 12 North Korean divisions, committed to the Korean front, and more than a million enemy troops stationed in reserve near the Yalu.

In late December, Ridgway, in establishing the defensive line along the 38th parallel, concentrated the bulk of the Eighth Army in the central and western sectors because of the obvious enemy concentration above Seoul. The west flank was held by the I Corps; the central sector by the IX Corps; and the ROK I, II, and III Corps held the eastern mountainous sector. The X Corps was reorganizing near Pusan. The

1st Marine Division, until recently a part of the X Corps, was held in Eighth Army reserve.

The New Year Offensive. At daybreak on 1 January 1951, after a night of mortar and artillery bombardment, the enemy launched an attack all along the U.N. line. The main effort was directed against the U.S. I and IX Corps in the west and central sectors. A force of seven Chinese armies and two North Korean corps pushed deeply into the U.N. line toward Seoul in the west and Wonju in the center.

and

As the offensive gained momentum, Ridgway ordered the U.N. forces to fall back to a line which ran along the south bank of the frozen Han River to Yangp'yang, through Hongch'on Chunmunjin to the Sea of Japan. A delaying force remained around Seoul to deny the enemy use of the Han River bridges. When the attacking forces, following up their initial success, crossed the Han to the east and west of Seoul, it became clear that the Seoul bridgehead could not be held any longer. Ridgway, following a policy of rolling with the punch rather than risking destruction by defending in place, decided to withdraw south to a line in the vicinity of the 37th parallel on 3 January. This line ran from P'yongť'aek, east through Ansong, northeast to Wonju, and in an irregular trace to the east coast town of Samch'ok. When Seoul fell on 4 January, the port of Inch'on was also evacuated.

After the fall of Seoul, Chinese attacks tapered off in the west. Many enemy units were shifted eastward so as to be in position to attack southwestward behind the U.S. I and IX Corps, and capture Wonju and the railroad and highway between Hongch'on and Pusan, the main U.N. north-south supply route. Wonju was abandoned by U.N. forces on 7 January. By 10 January large numbers of the enemy had passed through the gap and into the defensive zone of the ROK III Corps. To meet this threat Ridgway ordered the 1st Marine Division to prevent the enemy penetration from north of the Andong-Yongdok road on the east, and to protect the supply routes of the ROK units.

In the western sector, which was com

paratively quiet, Ridgway planned Operation WOLFHOUND, a reconnaissance in force in the I Corps sector, to reestablish contact and secure more exact information about the enemy. On 15 January the task force-the 27th Infantry Regiment, reinforced-advanced northward along the Seoul highway toward Osan. On the 16th it reached Suwon with practically no opposition. Satisfied by the reconnaissance, the U.N. Command ordered the task force to withdraw south.

By the third week in January the situation in the central and eastern sectors had eased, and pressure on our troops was gradually decreasing. However, although quiet prevailed on the front, air reconnaissance revealed that the enemy was accumulating reserves of supplies and bringing up thousands of replacements.

A reconnaissance in force by elements of the 1st Cavalry Division on 22 January revealed that the enemy had withdrawn from frontline positions. The task force returned after having met little resistance. Ridgway then scheduled a larger reconnaissance in force, Operation THUNDERBOLT, with each Corps using one U.S. division and one ROK regiment. The operation began on 25 January and advanced slowly and cautiously against light resistance during the rest of the month. (First U.N. Counteroffensive-25 January to 21 April 1951.) U.N. air support destroyed points of resistance and the enemy's lines of communication were subjected to damaging attacks, which kept a large part of his supplies from reaching the front. By 30 January his resistance stiffened and it continued to be vigorous until 9 February. Then it abruptly gave way. By 10 February U.N. forces secured Inch'on and Kimpo airfield, and the U.S. I Corps closed up to the south bank of the Han River.

On the central front, U.N. armored patrols reached the deserted city of Wonju and elements of the X Corps captured Hoengsong on 2 February against light resistance. On 5 February the X Corps began Operation ROUNDUP, a plan calling for ROK units of the Corps to disrupt the regrouping of North Korean forces south of the town of Hongch'on. On the second day of the

attack the ROK units met stiffening resistance, and pressure on the X Corps increased steadily as signs pointed to a large enemy buildup on its front. On the night of 11-12 February, Chinese Communist forces struck the ROK divisions north of Hoengsong and made immediate penetrations which forced the ROK troops to fall back rapidly. U.N. troops withdrew south toward Wonju and abandoned Hoengsong on 13 February. On this same day enemy forces struck at Chip'yong-ni, a road junction and key point of the central zone. The U.S. 23d Infantry Regiment and the French Battalion, forming a defensive perimeter around the town, held off a force of three Chinese Communist divisions for three days before enemy pressure melted away. Meanwhile elements of the U.S. 7th Division and ROK units formed a defensive line north of Chech'on, to check a strong enemy force attacking northeast of Wonju.

In the west the U.S. I and IX Corps were gradually taking all ground in the zones up to the Han River, except for a sizeable enemy foothold south of the Han in an area between Seoul and Yangp'yong. On the night of 13-14 February the enemy launched a powerful counterattack from this area toward Suwon, but his effort was quickly contained with heavy losses to his troops. Meanwhile areas far to the south were being harassed by guerrillas and remnants of North Korean troops. U.N. counteractions succeeded in reducing these forces to about 18,000 by the end of February.

On 18 February combat patrols confirmed a report of the IX Corps that enemy forces along the entire central front were withdrawing. Thereupon Ridgway ordered the IX Corps to move forward, which it did against light scattered resistance. By 19 February the initiative all along the front had passed into U.N. hands.

Ridgway was determined to give the North Koreans and Chinese Communists neither rest nor opportunity to reorganize. On 21 February he launched a general advance (Operation KILLER) by the U.S. IX and X Corps to deny important positions to the enemy and to destroy as many enemy troops as could be found. The objective was a

line running eastward from Yangp'yong to the Han River east of Seoul, thence to points north of Chip'yong-ni and Hwangsong-ni, and thence eastward so as to secure the east-west portion of the Wonju-Kangnung road between Wonju and Pangnimni.

Advances in both Corps zones were slow and unspectacular. The spring thaw and heavy rains caused swollen streams and deep mud which greatly hampered military operations. By 28 February the U.N. forces advanced to their assigned objectives, and the Communist foothold south of the Han collapsed. By 1 March the entire Eighth Army line was relatively stable.

Crossing the 38th Parallel. Although the Eighth Army had attained its geographical objectives by 1 March, a large part of the enemy had succeeded in withdrawing during the bad weather which had disrupted Allied road and rail movement. With approval by MacArthur, Ridgway planned to continue the attack northward in the central and eastern sectors with Operation RIPPER, to seize Hongch'on and Ch'unch'on and a line designated IDAHO just south of the 38th parallel.

RIPPER began on 7 March 1951. After overcoming initial resistance, the IX Corps reached the first phase line on 11 March and began the attack to the second phase line on the 14th. U.N. patrols moved into the deserted city of Seoul on the night of 14-15 March, marking the fourth time that the capital had changed hands. In the X Corps zone, terrain rather than hostile forces proved to be the greatest obstacle; but despite the enemy and natural obstacles Operation RIPPER ground forward. In the east, ROK units were ordered to destroy the remnants of a North Korean division which had infiltrated southward in January. By 17 March, with this threat eliminated, the ROK forces had moved to Line IDAHO. U.N. forces entered Ch'unch'on, an enemy supply and communications center, on 19 March.

On 23 March the 187th Airborne RCT dropped at Munsan-ni, about 20 miles northwest of Seoul, to trap enemy troops fleeing northward; but because of the rapid enemy withdrawal it failed to achieve its purpose.

By the last of March Ridgway's forces had fought their way generally to the 38th parallel in position along line IDAHO. Again the U.N. Command was faced with the problem of crossing the parallel into North Korea.

Ridgway, with the approval of President Truman and MacArthur, elected to continue the advance, with the hope of achieving maximum destruction of enemy forces. U.N. commanders made their plans to advance with the knowledge that the enemy was engaged in a full-scale buildup of troops and materiel for his expected spring offensive.

On 5 April Ridgway opened Operation RUGGED, a general advance toward a new objective line called KANSAS. This line, running along the commanding ground north of the 38th parallel, was 115 miles long, including 14 miles of tidal water on the left flank and the 10-mile water barrier of the Hwach'on Dam in the center. By 9 April the U.S. I and IX Corps and the ROK I Corps on the east coast had reached Line KANSAS, and the U.S. X and ROK III Corps in the central and central-east sectors were drawing up to it. The I and IX Corps continued to advance, attacking Ch'orwon, with the intention of seizing a line designated UTAH, an outward bulge of KANSAS, so as to be in a position to strike at the "Iron Triangle."

On 11 April President Truman relieved General MacArthur of all his commands because of differences over national policy and military strategy, and replaced him with General Ridgway. Lt. Gen. James A. Van Fleet assumed command of the Eighth Army on 14 April, replacing Ridgway.

Meanwhile U.N. forces continued to edge forward. The Hwach'on Dam was taken on 16 April. On the east coast South Korean forces captured Taep'o-ri. Other ROK troops north of Seoul sent patrols across the Imjin River and far to the northeast. By 17 April U.N. units could not make contact with the enemy, and thereafter the general advance toward Line UTAH was virtually unopposed. Even as it continued, however, evidences of enemy preparations for a

counterattack were apparent to the Eighth Army Command. By 19 April all U.S. I and IX Corps units were in positions along Line UTAH, preparing for an advance to a new Line WYOMING. On 22 April enemy activity across the whole front suddenly increased and the U.N. advance halted abruptly. The expected spring offensive was at hand.

Enemy Spring Offensive. Following a four-hour artillery bombardment, three Chinese Communist armies attacked the U.N. line in the evening hours of 22 April (CCF Spring Offensive-22 April to 8 July 1951). The main attack was against the U.N. I and IX Corps in the Seoul sector, coupled with a secondary thrust in the central Yonch'on-Hwach'on area and a push in the east near Inje. U.N. lines held firm except in the IX Corps central sector, where ROK units were forced back in confusion. With the line broken, Van Fleet ordered the I and IX Corps to withdraw through a series of delaying positions to Line KANSAS, thus giving up the ground gained in recent U.N. offensives. When the enemy cut the Seoul-Kansong highway on 26 April, Van Fleet withdrew the IX Corps back to the Hongch'on River.

Meanwhile, in the I Corps area, the enemy crossed the Imjin River on 22 April and drove the ROK units south of the KANSAS Line on the 23d. On 27 April the enemy outflanked Uijongbu, forcing U.N. units to pull back to within four miles of Seoul, and also made an unsuccessful attempt to outflank the city to the east. On the east-central front North Koreans captured Inje. By 29 April, however, their drive had been halted. On this date Van Fleet established a new line, designated NONAME-LINE, extending from north of Seoul to Sabangue and thence northeast across the 38th parallel to Taepo-ri on the east coast. Because the major enemy attack had been in the west, Van Fleet reshuffled his units to put more American divisions there. By the end of April, U.N. forces had stopped the enemy short of Seoul and the Han and held a strong, continuous defense line.

As the enemy withdrew to recoup losses, Van Fleet improved his defenses on NO-NAME-LINE and planned an offensive to carry the Eighth Army back to Line KANSAS; but signs of another impending enemy attack led him to postpone it.

On the night of 15-16 May an estimated 21 Chinese divisions, flanked by 3 North Korean divisions in the west and 6 in the east, struck in the central sector against the U.S. X and the ROK III Corps in the Naep'yong-ni-No-dong area. ROK units were again forced back by the swarming columns of Chinese and North Koreans. Once more Van Fleet reshuffled his units, moved in reserves, and laid down a tremendous curtain of artillery fire which exacted heavy casualties and stopped the enemy offensive.

On 17 May the enemy struck down the Pukhan River toward the Han in the western sector, against the I and IX Corps, with a force of about 25,000 men. This attack was also contained after three days of violent action. By 20 May U.N. troops brought the enemy to a standstill, having thus stopped two major offensives in two months.

U.N. Forces Resume the Advance. Van Fleet decided to renew the offensive, so as to give the enemy no chance to gather himself for another counterstrike. On 18 May he opened a series of local attacks. Once more enemy forces pulled back and U.N. forces moved forward against light resistance. Within a few days the I Corps reached the Imjin River north of Munsan-ni and entered Uijongbu and Sinp'al-li. The IX Corps pushed toward Kap'yong, drove the enemy across the Hanch'on River, and moved toward the Hwach'on Reservoir. In the X Corps area the 1st Marine Division attacked Yanggu on 24 May. The 187th RCT headed for Inje, which it captured on the 27th. The Marines were pushing toward the Hwach'on Reservoir and Yanggu. The 7th Division of the IX Corps took Hwach'on. By 31 May the U.N. forces scored a significant advance which brought them just about back to the KANSAS Line, and South Korea was virtually cleared of the enemy.

At this point the Joint Chiefs of Staff prescribed that the Eighth Army was

not to go beyond the general vicinity of Line KANSAS. The only tactical operations permitted were those necessary to protect itself, to maintain contact, and to harass the enemy. This was the basic pattern of U.N. military operations which was to be followed throughout the remainder of the war.

On 1 June, therefore, Van Fleet ordered his reserve forces to strengthen KANSAS so as to make it virtually impregnable. Meanwhile the I and IX Corps were to continue Operation PILEDRIVER toward Line WYOMING (the bulge north of KANSAS that ran from the Imjin River to points just south of Ch'orwon and Kumhwa and thence southeast). Ch'orwon and Kumhwa were captured on 11 June. Two tankinfantry task forces reached P'yongyang, the northern tip of the Iron Triangle, on 13 June and found it deserted. The dominating high ground north of the city was held by the enemy, however, and U.N. forces withdrew. The Chinese reoccupied P'yongyang on 17 June. Meanwhile the X Corps on the eastcentral front pushed through mountains toward its sector of the KANSAS Line, which extended over a series of ridges from the Hwach'on Reservoir northeastward to the lower lip of the "Punchbowl," an aptly named circular depression north of Inje. Thus by midJune the Eighth Army had attained the principal terrain objectives of Operation PILEDRIVER. Action for the rest of the month was confined to developing the KANSAS and WYOMING Lines, and to patrolling and local clashes.

THE PERIOD 23 JUNE 1951-31 DECEMBER 1952. Truce Negotiations. On 23 June 1951 Jacob Malik, Deputy Foreign Minister of the U.S.S.R., made a statement in a recorded broadcast in New York implying Chinese and North Korean willingness to discuss armistice terms to end the Korean War. When Communist China indicated that it also desired peace, President Truman authorized General Ridgway to arrange for an armistice conference with the North Korean commander. Both sides agreed to begin negotiations at Kaesong on 10 July 1951. The chief delegate for the U.N. at the conference was Vice Admiral C. Turner Joy. The enemy delegation was led by Lt. Gen. Nam II.