Red China on the Offensive

By Lynn Montross
Historical Division, Headquarters, U.S. Marine Corps
Reprinted from February 1952 issue of the Marine Corps Gazette
Reprinted with permission to The Korean War Educator

The word “reservoir” has a special meaning in the traditions of the U.S. Marine Corps It will always call to memory a column of parka-clad Leathernecks fighting in the bitter cold of December 1950—the men of the 1st Marine Division who cut their way home from the Chosin Reservoir to Hamhung through eight CCF divisions.

Yet there is another artificial lake that deserves a chapter in Marine history. It is the Hwachon Reservoir, a mountain-locked body of water lying just north of the 38th parallel along the rocky spinal column of Korea. For it was in this area that the 1st Mar Div had some of its hardest and least known actions—fights worthy of comparison with the battles of Inchon-Seoul and the Chosin Reservoir.

The time was April 1951. And the occasion was the beginning of the enemy’s double-barreled Spring Offensive, with Red China shooting the works for a decision in Korea.

This effort did not come as any surprise. There was not even much mystery as to when and where the initial blows would fall. The Eighth U.S. Army had been given timely and accurate reports of the enemy’s build-up. But nothing is certain in war except uncertainty, and it could not have been foreseen that a secondary CCF effort would lead to a sudden breakthrough west of Hwachon Reservoir.

This easy penetration, which may have astonished the Chinese themselves, exposed the entire left flank of the 1st Mar Div by opening a gap in the adjoining sector held by a ROK division. The Leathernecks were threatened with envelopment, and it took some vigorous fighting and maneuvering to prevent the enemy from exploiting his advantage.

Captured documents made it plain that the Communist purpose was nothing less than the destruction of the Eighth Army and eviction of United Nations forces from Korea. This ambitious program was to be carried out by an army estimated at about 700,000 CCF and North Korean troops, not counting units training in Manchuria.

Major counter-offensives had been launched twice before by Red China. Late in November 950 and again on the last night of the year, the invaders struck along a trans-peninsular front. Total advances of some 200 miles were made, yet these territorial gains could not compensate for appalling casualties. For the Eighth Army and its allied Republic of Korea divisions were still intact after withdrawing to final defense lines. Every man in te ranks realized, moreover, that ground had been sacrificed rather than personnel and equipment when the Communist pressure became too heavy.

The proof of Eighth Army fighting spirit was demonstrated shortly after the end of the second CCF effort. LtGen Matthew B. Ridgway, the new Eighth Army commander, immediately launched the first of a series of limited UN offensives. While one of these drives was in progress, another was being planned and activated on a still larger scale. Thus from 15 January to 22 April 1951 the UN forces were continually striking, and the initial reconnaissance force by an RCT had grown into th coordinated advance of three corps.

One UN operation, coming to a finish on 4 March, was followed three days later by the jump-off of another. Both offensives, like their forerunners, were planned primarily for the purpose of inflicting damage on the enemy. Gen Ridgway constantly stressed the need for security and cautioned his corps commanders to observe his three basic tenets: “coordination, maximum punishment, and maintenance intact of major units.”

Another primary purpose was to keep the enemy off balance and disrupt his obvious build-up for a new counter-offensive. And though the gaining of ground was considered secondary, plans for the March offensive envisioned a northward advance to a strong UN line which could be used either for offense or defense.

“Good footwork…combined with firepower”—this was Gen Ridgway’s formula for victory over a numerically superior enemy. It paid off so well that most of the objectives were secured by the end of March. Seoul had been reoccupied without a fight by UN forces nearing the 38th parallel after gains of about 50 kilometers.

Only in one respect had the results been unsatisfactory—the damage inflicted on the enemy, heavy as it was, fell below expectations. That was because the Chinese had conserved their forces by delaying tactics suited to the mountainous terrain. Small units put up a temporary defense to screen withdrawals in the rear, then pulled back to prepared positions.

On 29 March, therefore, Gen Ridgway published a plan for continuing the momentum of the drive and adding to its accomplishments. The assault troops jumped off again on 2 April, and the Eighth Army ground on methodically to new objectives as the enemy continued to retreat.

The Communist forces might have been compared to an antagonist backtracking to get set for taking aim with the shotgun. There could be no question about both barrels being loaded, for CCF offensive movements were reported daily on a basis of air sightings. Undoubtedly the enemy would pull the trigger at his first opportunity, but meanwhile the footwork and firepower of the Eighth Army continued to keep him off balance.

Chunchon was abandoned, just as Hongchon had been, by Communists who kept up their delaying tactics while retreating north of the 38th parallel. This was the situation when LtGen James A. VanFleet assumed command of the Eighth Army on 14 April, after Gen Ridgway was named the new supreme commander to succeed General of the Army Douglas MacArthur.

Gen Van Fleet, formerly head of the American Military Mission in Greece, visited one CP after another while pressing the UN advance. Although the Communists continued to retreat, reports indicated that 12 corps, numbering three divisions each, were poised behind the front for a counter-stroke. Movements of troops and supply vehicles were screened by the smoke of burning brush, but the enemy appeared to be preparing for a major attack in the Seoul area and a secondary effort on the central front.

Not only was the CCF counterstroke a foregone conclusion, but it could also be assumed that further UN advances would force the enemy’s hand. Already the UN forces were within striking distance of the so-called “Iron Triange”—the comparatively level Chorwon-Pyonggang-Kumhwa area where the Chinese had utilized a good network of roads to concentrate for their offensive. The enemy would soon have to stand or attack, and the Eighth Army plan was flexible enough to provide for an orderly withdrawal to lines suited to an aggressive defense. This concept was in line with the Eighth Army policy of placing less value on positions than men and equipment, but the attack was to continue vigorously toward the approaches to the Iron Triangle.

On 21 April, after a brief build-up, the assault units of I and IX Corps renewed an advance calculated to goad the enemy into action. The 1st Mar Div, as part of IX Corps, had as its objective the Hwachon Dam on the southeastern approaches to the Iron Triangle.

The enemy had recently held this area, and it seemed likely that another stubborn defense would be made. On the first day, however, the Leathernecks met almost no opposition, and by the afternoon of the 22d they reached their objectives. The enemy had put up a fight at the Hwachon Dam, but the 1st Korean Marine Corps Regiment took the position after forcing a crossing of the Pukhan River in DUKWs and rubber boats.

This unit, composed of Koreans trained by U.S. Marines, had distinguished itself as a fourth RCT of the 1st Mar Div during the past month. Thus on the evening of 22 April the lineup consisted from left to right of RCT-7, RCT-5 and the 1st KMC Regt, with RCT-1 in reserve. A ROK division held the sector to the west, and to the east was an infantry division of X Corps.

The first few hours of darkness passed quietly. Resistance had been light everywhere on the Eighth Army front, and officers in the various CPs were planning a next day’s advance which was never to materialize. For the first CCF attacks began at 2215 on the central front and continued throughout the night. The enemy had pulled the trigger on his long expected counter-offensive.

Before midnight the 1st Mar Div was notified by corps that the Chinese had smashed through the lines of the ROK division in their sector to the west. The penetration, extending to a point about three and a half miles south of the MLR, had opened a gap of 1,000 yards between the Marines and the nearest ROK unit.

Orders for the next day’s attack were cancelled as the 1st Mar Div ordered the three forward regiments to consolidate for defense and patrol to the front. RCT-1, in reserve, was directed to send a battalion to the divisional left flank with a mission of blocking CCF attempts at envelopment. The assignment fell to the reinforced 1st Bn, which moved out at 0100 with a platoon of 4.2 mortars.

These preparations came just in the nick of time. Within the next two hours the 1st Mar Div was beating off CCF attacks on both flanks. On the left a force of undetermined numbers struck the 1st Bn of RCT-7 with mortars, small arms, and automatic weapons. The enemy pulled back at 0300, after getting the worst of a grenade duel, only to try again an hour later in estimated battalion strength. Able Co received more than its share of the assault, but counter-attacked to wipe out a Chinese infiltration and restore the lines before the enemy withdrew at daybreak.

On the divisional right flank, just west of the Hwachon Dam, the KMC Regt repulsed a succession of assaults which lasted into the daylight hours. Both regimental flanks were threatened, and on the left the enemy nearly surrounded a company of the 1st Bn. Only a platoon remained on position at 0400, when a counter-attack regained the lost ground.

RCT-5 had its turn after the Chinese infiltrated along a ridgeline in the darkness to occupy Hill 313, dominating the town of Hwachon. The enemy was holding the crest when elements of 1/5 attacked against small arms and automatic fire. An air strike was called in support, but meanwhile the infantry stormed up the slope to drive off an estimated 150 to 200 CCF troops.

On the morning of the 23d the 1st Mar Div still held firm after defeating all enemy attempts at envelopment. But this was only the first found, and renewed CCF attacks could be expected on the wide open left flank. In anticipation of this danger, Corps ordered the 1st Mar Div to fall back. This maneuver might be compared to closing a gate in the face of the enemy. Pivoting on the right flank, while swinging southward along the exposed left flank, the division pulled back to a new diagonal line about six miles to the rear at its maximum depth.

RCT-5 and the KMC Regt fell back without enemy interference. A more difficult task awaited RCT-7, and the 2d Bn covered the withdrawal of the 1st while helicopters evacuated the wounded. This regiment assumed control of the 1st Bn of RCT-1, and the other two battalions were brought up from reserve by division orders to dig in along a ridgeline about two miles south on the divisional left flank. Thus the positions were not tied-in, and it was a reasonable conjecture that this line could afford only a temporary defense.

The readjustment of positions was completed by nightfall, when the three regiments awaited the attack. It was not long in coming, for Corps had not yet been able to bring up enough reserves to close the dangerous gap to the west. Soon after darkness the enemy struck from two directions, making a secondary effort in the north while attempting to turn the Marine left flank.

Veterans of Inchon-Seoul and the Chosin Reservoir could remember few occasions when Marines had a tougher fight. For the entire division was involved all night and most of the following day, with the 11th Marines and other supporting arms backing up the four infantry regiments.

Just as the blow of a whip is most vicious where the lash curls around its target, the CCF attack was hardest on the left flank of the 1st Mar Div. On the opposite flank, the KMC Regt and RCT-5 were least heavily engaged, though under attack or fire the whole night. RCT-7, farther to the west, had a rougher time of it. But it was RCT-1 on the extreme left which caught the full fury of the CCF effort. Here the tactical lash cut deeply into Marine positions, and the two isolated battalions had an all-night battle to hold their ground.

The Chinese made some use of mortar and artillery fire. But for the most part they relied on small arms and automatic weapons while infiltrating through the darkness to a point near enough for throwing grenades. And having recently retreated from this area, the officers had an intimate knowledge of ridges and draws leading into Marine territory.

The Leathernecks had to maneuver as well as fight. Shortly after midnight, Corps notified Division that withdrawals to a new defensive line would be necessary. Thus after beating off CCF attacks all night, the 1st Mar Div was up against the problem of pulling back under fire in broad daylight.

Typical of the critical actions on the hard-pressed Marine left flank was the effort made by the enemy in estimated regimental strength to cut off the 3d Bn of RCT-1, dug in along a ridge. The Chinese kept up their assaults all night, despite heavy losses, without effecting a penetration. At 0930 on the 24th the battalion was still holding its ground, though nearly out of ammunition and in danger of being surrounded.

Not only was the 3d Bn itself in peril, but the entire division was endangered. Division orders to withdraw were executed by 3/1 under heavy CCF automatic and small arms fire as the men fell back through the 2d Bn, which covered a retirement further supported by artillery and air strikes. When the 2d Bn pulled out in its turn, the enemy managed to cut off and destroy two jeeps.

The 1st Bn, which had been hotly engaged on the left of 1/7, was released that morning from operational control of RCT-7. Under enemy pressure the three reunited battalions of RCT-1 completed their withdrawal and dug in on high ground. Again they held a line facing west, so as to repel further enemy attacks from that critical direction.

The KMC Regt and RCT-5 had no opposition when breaking off contact with the enemy and taking their positions along the new defensive line of 24 April. This line was so much shorter that RCT-7 was withdrawn altogether and given rear area security missions.

Two Chinese probing attacks were repulsed on the night of 24-25 April by the 2d and 3d Bns of RCT-1. Quiet prevailed elsewhere on the 1st Mar Div front except for a few mortar rounds lobbed into the positions of RCT-5.

Patrols sent out on the 25th by the 1st and 3d Bns of RCT-1 had no difficulty in making contact. The 3/1 patrol became heavily engaged only 200 yards from its own battalion positions, and the 1/1 patrol had to be extricated by tanks. In the RCT-5 sector, however, a tank-infantry patrol made no contacts in the 1/5 sector, and two 2/5 patrols ranged as far out as 1,500 yards without finding any enemy.

These tests having confirmed that the left flank was still the most vulnerable spot, added security was gained by attaching 3/7 to the left of 2/1, thus extending the defensive positions still farther southward. Here the Marine line was bent to resemble a fishhook with its shank to the north and the barb curving around to the west and south. This analogy may also have occurred to the enemy, for there were only cautious nibbles on the night of 24-25 April in the form of two light probing attacks. The fires of the 11th Marines were required, however, to break up attempted CCF concentrations in front of the positions held by RCT-1.

There was still some pressure on the left flank during then night of 25-26 April, but the 11th Marines continued to prevent the enemy from mounting a large-scale attack. On the other side of the gap left by the CCF breakthrough, a U.S. infantry division also extended its vulnerable flank to the southward. These defensive measures enabled IX Corps to send up reserves, and on the 26th, Gen Van Fleet published an order on a change in strategy.

Ever since January the Eighth Army had been “rolling with the punches” to contain enemy counterstrokes—giving up ground while inflicting all possible damage. But this time the commanding general decided to break off contact and fall back as much as 20 miles in some sectors to a new defensive line. And though Seoul had not previously been considered of primary importance, Gen Van Fleet directed that it was to be defended and held.

All along the Eighth Army front the rearward movement began on the 25th. The 1st Mar Div was to withdraw in two stages—first, to positions covering Chunchon until service units could retire from that town; and, later, to the new defensive line. This meant that RCT-1 (with 3/7 attached) and RCT-5 were to be pulled back across the Pukhan River, while the KMC Regt on the right needed only to retire in zone.

The movement began at 1130 on 26 April without CCF interference. By 1900 all units except 2/1 and 3/7 were across the bridge, and the span was destroyed. These battalions forded the waist-deep stream in the darkness, crossing at 0230 and moving toward their new positions covering Chunchon.

It has always been a proud Marine tradition that a helpless comrade must not be neglected, and that night the men of 2/1 lent a supporting hand to a dim figure stumbling along in the darkness. It was necessary to hold him up while fording the river, and event o boost him occasionally while climbing hills. The poor fellow was apparently too exhausted to speak, and not until daybreak did the Leathernecks discover that they had been succoring a frightened Chinese straggler who infiltrated into their lines to give himself up. He was the single prisoner taken by the division that day.

By the morning of the 27th the first phase of the withdrawal had been completed. The second phase began the next day, but owing to a shortage of vehicles, it was not until the morning of the 30th that the last unit of the 1st Mar Div took its assigned position on the new defensive line.

During the Marine operations of the past week, the entire UN front had of course been struck by the CCF counter-offensive. The forward movement of the Eighth Army was stopped in its tracks on the night of the 22d, and some of the units did not weather the attacks of the next few days without losses both of territory and personnel.

The most dramatic of these reverses took place on the west central front. Both the British 29th Brigade and the Belgian battalion came under terrific pressure from Chinese forces attempting to cut off and surround UN units. The enemy found his opportunity when a battalion of the British 29th Brigade was left isolated in the confusion of a general withdrawal, ordered by Gen Van Fleet on 23 April, to prepared lines of defense. Cut off and surrounded, the 1st Bn of the Gloucesters fought on for 70 hours until supplies of food and water reached the vanishing point. When radios went dead and ammunition ran out, LtCol F. J. Carne, British Army, directed his survivors to scatter in small groups and try to make their way back to the UN lines. Only about 40 men succeeded after battling their way northward through enemy forces, then circling around to the south until they encountered a friendly armored column.

With an estimated 70 divisions south of the Yalu, the enemy deployed about 36 of them between Hwachon and the west coast and some 12 to 14 from Hwachon to the east coast. Reports had not erred, as events were to prove, in predicting that the chief CCF blow would be aimed at the Yangchon-Uijongbu-Seoul corridor in the west, with a diversionary effort being made in the east-central front. At first, it is true, the sudden success of the sideshow gave it the illusion of more importance than the main act. But the enemy profited little from his breakthrough, and by the 26th the east-central front was stabilized.

It was on this date that the main enemy effort revealed itself as an attempt to smash through and capture Seoul. CCF divisions closed in from two directions on Uijongbu, compelling elements of a U.S. infantry division to pull back to prepared positions about four miles north of the ROK capital.

The Chinese, it was believed, had set themselves the goal of sacking the city on May Day, the world-wide Communist holiday. In this aspiration they were destined to be disappointed. The enemy tried to work around the left flank by crossing the Han to the Kimpo Peninsula, but air strikes and potential naval gunfire quickly frustrated this maneuver. Another flanking attempt 35 miles to the southeast met repulse, and by the end of the month it was apparent that the Communists would not celebrate May Day in Seoul.

Four days earlier the Chinese had shot their bolt on the east-central front, and a diversionary attack in ROK sectors to the east had resulted only in the capture of Inje. Thus the first phase of the CCF counteroffensive had failed to accomplish any of its announced aims, though UN estimates placed the enemy casualties as high as 70,000 during the seven days.

But this was only the first act. The Chinese were believed to have committed about half of their immediately available strength. Eighth Army staff officers concluded, therefore, that the lull at the end of April was temporary and would be followed by a renewal of the offensive. The enemy, in short, had fired only one barrel.

Seventeen CCF divisions were believed to be available for a second performance, and Gen Van Fleet called a conference of corps commanders at his CP on 30 April. Staff officers announced that the Eighth Army was planning to take a calculated risk by reorganizing tactical elements in preparation for the next enemy attempt.

After this reshuffling, the Eighth Army was to hold on its defensive line until the time came for striking again. Each corps would have its definite missions, and Gen Van Fleet enjoined them to “keep units intact. Small units must be kept within supporting distance.”

It was the commanding general’s intention to conduct an active and dynamic defense. He reiterated that he wanted more mines and tactical wire, covered by fire. “We must expend steel and fire,” he declared, “Not men. I want to stop the enemy here and hurt him.” But he also directed that aggressive patrolling be conducted by tank-infantry teams for the purpose of unmasking the enemy’s preparations.

On 1 May, after the reshuffling of units, the 1st Mar Div found itself back again in X Corps under LtGen Edward S. Almond. The transition had been simple. A left-flank battalion was relieved by a U.S. infantry division, so that this division could be placed in line on the Marine left and the corps boundary shifted westward. On the Marine right was another U.S. division.

The 1st Mar Div, as well as other Eighth Army units, soon began the preparation of defenses in depth—defenses bristling with mines, barbed wire entanglements, and meticulously plotted fields of fire. On 6 May, in response to corps orders, the Marines helped to patrol along the right boundary in conjunction with elements of the adjacent U.S. infantry division. RCT-7 was moved forward several miles for this purpose, and the 1st Bn of RCT-1 brought up from reserve to cover the resulting gap with patrols.

Patrolling went on vigorously along the entire 1st Mar Div front during the next ten days. Several of the larger tank-infantry teams penetrated as far as the Pukhan River, and Chunchon was entered without opposition. These actions confirmed the existence of a wide “no-man’s land,” held by neither side in force, and the Leathernecks had only a few minor clashes with enemy groups.

The same situation prevailed over the entire Eighth Army front. Units from all three corps ranged forward as much as 15 kilometers with only negligible contacts.

Gen Van Fleet did not content himself with probing. For the purpose of coming to grips with the enemy as well as securing a supply route, he planned a limited offensive of the ROK Army to begin on 7 May. Navy forces on the east coast laid down a preliminary bombardment and simulated an amphibious assault on Kansong while the Fifth Air Force conducted strategic bombing missions. In conjunction with these attacks in the east, the 1st ROK Div of I Corps was directed to conduct a two-day reconnaissance in force along the west coast.

Both small-scale offensives exploded in the face of an enemy preparing for a renewal of his own offensive. The 1st ROK Div completed its mission on 9 May without discovering evidences of an enemy build-up. In the ROK sector, slow progress was made against delaying tactics; but coastal units went forward under cover of naval gunfire to capture Kansong on 9 May.

This was the day when Gen van Fleet published his plan for a much more comprehensive drive. His purpose was to break up enemy preparations by threatening lines of communications and supply, and all three U.S. corps were to push toward objectives just south of the 38th parallel. Within the next few days, however, preparations for this operation were postponed because the massing of CCF troops indicated the possibility of an enemy offensive in the east instead of west. Further reports made it seem likely that this offensive might materialize within 72 hours, and the commanding general decided to stand along the defensive line.

It is never safe to under-rate an enemy, but Eighth Army staff officers apparently gave Chinese generals too much credit when they anticipated a bid for a decision in the west. True it was that the chances for a surprise or temporary success were perhaps better in the east, but the rugged and almost roadless terrain made it difficult to exploit a victory. This entire littoral, however, was dominated by UN sea power.

In spite of these handicaps, the enemy struck on the 16th to the east of the 1st Mar Div. Several CCF diversionary attacks were begun simultaneously in Eighth Army sectors to the west.

The main blow was launched by an estimated 125,000 CCF troops in the Naepyong-Inje-Nodong area. Six divisions attacked on a 20-mile front in the vicinity of Hangye to break through the lines of two ROK divisions. Pouring into this gap, the Communists made a maximum penetration of about 30 miles which exposed the right flank of the U.S. infantry division on the west.

Gen Van Fleet acted promptly to plug the gap. Immediately after the breakthrough, he sent another U.S. infantry division, hen in reserve southwest of Seoul, on a 70-mile, all-night ride to the threatened area. The hard-pressed defenders were further aided by the 1st Mar Div, which had been on the receiving end of some of the first Communist attacks.

At 0300 on 17 May, the Chinese attempted to wipe out the perimeter and roadblock which had recently been set up by the reinforced 3d Bn of RCT-7. The enemy attacked in wave after wave with a wide variety of weapons—mortars, recoilless rifles, satchel charges, grenades, small arms, and automatic weapons.

These attacks were made with suicidal desperation. Chinese soldiers, two of them wearing U.S. Marine uniforms, were killed after climbing onto the tanks of Dog Co., 1st Tank Bn, and shouting, “Tank, let me in!” One Marine tank was disabled by a hand grenade thrown into the engine compartment, and another damaged by a satchel charge. The enemy tried to disable a third tank by rolling up a drum of gasoline and igniting it, but the Marine crew pulled away.

The reinforced Marine battalion beat off the assaults of Chinese in estimated regimental strength, but it was a hard struggle resulting in grenade duels and hand-to-hand fighting. At 0630 the enemy attempted to withdraw, but the howitzers of the 11th Marines and the planes of the 1st Marine Aircraft Wing had their turn. Enemy casualties were estimated at 350 killed (112 counted), 550 wounded, and 82 prisoners. The captured CCF weapons included recoilless rifles, mortars, and Russian machine guns.

On the 18th the 1st Mar Div, carrying out X Corps orders, began a maneuver designed to aid the U.S. division on the east by narrowing its front. RCT-7 was pulled back to relieve RCT-1, which side-slipped to the east to take over an area held by elements of the adjacent division. RCT-5 then swung around from the divisional left flank to the extreme right. These shifts enabled the other division to face east and repulse attacks on its flanks.

This was the climax. From 19 May onward it grew more apparent every hour that the second CCF counter-offensive had failed even more conclusively than the first. The enemy had only a narrow penetration on a secondary front to show for frightful casualties, and after four days his main attack had lost most of its momentum.

Worse yet, from the Chinese viewpoint, was the fact that the UN forces were in position to strike a return blow before the attackers recovered their tactical balance. The Eighth Army had emerged with comparatively light losses after taking every punch the attackers could throw, and now it was about to swing from the heels. Armored patrols sent out on the 20th and 21st found the Communists vulnerable in some areas, and next day the Eighth Army began a counter-attack which turned into a pursuit in some sectors of the front.