THE KOREAN WAR

RESTORING THE BALANCE

25 January–8 July 1951
Introduction

The Korean War was the first major armed clash between Free

World and Communist forces, as the so-called Cold War turned hot. The

half-century that now separates us from that conflict, however, has

dimmed our collective memory. Many Korean War veterans have considered themselves forgotten, their place in history sandwiched between the

sheer size of World War II and the fierce controversies of the Vietnam

War. The recently built Korean War Veterans Memorial on the National

Mall and the upcoming fiftieth anniversary commemorative events

should now provide well-deserved recognition. I hope that this series of

brochures on the campaigns of the Korean War will have a similar effect.

The Korean War still has much to teach us: about military preparedness, about global strategy, about combined operations in a military

alliance facing blatant aggression, and about the courage and perseverance of the individual soldier. The modern world still lives with the consequences of a divided Korea and with a militarily strong, economically

weak, and unpredictable North Korea. The Korean War was waged on

land, on sea, and in the air over and near the Korean peninsula. It lasted

three years, the first of which was a seesaw struggle for control of the

peninsula, followed by two years of positional warfare as a backdrop to

extended cease-fire negotiations. The following essay is one of five

accessible and readable studies designed to enhance understanding of

the U.S. Army’s role and achievements in the Korean conflict. 

During the next several years the Army will be involved in many

fiftieth anniversary activities, from public ceremonies and staff rides to

professional development discussions and formal classroom training.

The commemoration will be supported by the publication of various

materials to help educate Americans about the war. These works will

provide great opportunities to learn about this important period in the

Army’s heritage of service to the nation.

This brochure was prepared in the U.S. Army Center of Military

History by John J. McGrath. I hope this absorbing account, with its list

of further readings, will stimulate further study and reflection. A complete listing of the Center of Military History’s available works on the

Korean War is included in the Center’s online catalog:

www.army.mil/cmh-pg/catalog/brochure.htm.

JOHN S. BROWN

Brigadier General, USA

Chief of Military History
Restoring the Balance

25 January–8 July 1951

The period from late January to early July 1951 was critical for the

United Nations (UN) Command in Korea. Recovering from the disastrous retreat that followed the Chinese Communist Forces (CCF) military intervention in November 1950, UN forces endured two massive

CCF campaigns that threatened to push them off the peninsula. Amid

desperate fighting, the UN troops managed to hold on, regroup, and

counterattack each enemy initiative, finally establishing a strong

defensive line across the middle of the peninsula. Their sacrifices

finally stabilized the battlefield and provided the foundation for the

cease-fire and negotiations that followed. 

These bitter struggles also saw a major shift in U.S. policy and

strategy. For American policymakers, the Korean War became an

economy of force operation with limited objectives. The World War II

concept of total victory and unconditional surrender was supplanted

by the more limited goal of restoring Republic of Korea (ROK or

South Korea) to its general prewar boundaries and implementing an

effective cease-fire agreement. As one of its unexpected consequences,

this strategic shift also saw the dismissal of the UN commander,

General of the Army Douglas MacArthur, when he openly criticized

the new limitations. But with the nuclear monopoly enjoyed by the

United States quickly fading, the threat of worldwide atomic war tempered the options available to U.S. officials. Campaign objectives were

thus increasingly limited to gaining control of key defensible terrain

and using battlefield attrition to force the other side into negotiations. 

Strategic Setting

Approximately 600 miles long and between 125 and 200 miles

wide, the Korean peninsula is mountainous and frequently cut by

waterways of all sizes generally flowing down from the mountains into

the sea. In the central section of the peninsula, where much of the

fighting in early 1951 occurred, the terrain was particularly rugged.

The western portion was a minor coastal plain marked by estuaries

formed from the Han, Imjin, and Pukhan Rivers. In the center, the

Hwach’on Reservoir was the most prominent feature. Except in the

most rugged areas, villages and towns dotted the landscape. The road

network was primitive and greatly affected by the weather. 
Unsan

38° 38°

T a e b

a

e k

M t s

MANCHURIA

Hyesanjin

Ch’osan

Hagaru-ri

Hungnam

Iwon

Wonsan

Sinuiju

Chongju Sinanju

P’YONGYANG

Kaesong

Ch’orwon

Munsan-ni

Uijongbu

Ch’unch’on

Hongch’on

Suwon

Osan

Ch’ungju

Wonju

Chech’on

Samch’ok

Ulchin

Andong

Yangyang

Kansong

Kosong

Kumhwa

P’yonggang

P’ohang-dong

Taegu

PUSAN

Miryang

Masan

Mokp’o

Kunsan

Taejon

SEOUL

Inch'on

an gjin

Ch R

CHANGJIN

(CHOSIN) RES

Ch’ongch’on

R

Taedo ng

Taeryong

Kur

R

R

yong

R Yalu R

Yesong R

Imjin R

Han

R

Naktong

R

Kum

R

YELLOW

SEA

K O R E A

S T R A I T

SEA

O F

JAPAN

KOREA

High Ground

Above 200 Meters

0 50 MILES
By January 1951 the Korean

War was six months old. The

invasion by North Korea

(Democratic People’s Republic of

Korea) in June 1950 had driven

the UN forces into a headlong

retreat to the Pusan Perimeter. In

a spectacular reversal of fortune,

the amphibious landing of UN

forces at Inch’on in midSeptember triggered a collapse of

the North Korean People’s Army

that was only stopped by the

enormity of the Chinese intervention in October and November.

The entry into the war of major

Chinese military forces rocked

the overextended UN troops and

sent them reeling back into South

Korea. For a time it seemed that

the UN forces might have to

abandon the peninsula, resulting

in a complete Communist victory.

Only by trading space for time and by pummeling the advancing

Chinese with artillery fire and air strikes did the new UN commander,

Lt. Gen. Matthew B. Ridgway, halt the enemy. 

Operations

On the eve of the renewal of full-scale UN offensive operations,

the Eighth Army consisted of 178,464 American soldiers and marines,

223,950 ROK Army troops, and UN ground contingents from

Australia, France, India, the Netherlands, the Philippines, Sweden,

Thailand, Turkey, and the United Kingdom. These forces were organized into five corps, from west to east: I, IX, and X and the ROK III

and I. In general, ROK forces held the more easily defended, rugged

terrain in the east, while U.S. forces were positioned on the lower, flatter areas in the west, where their greater mobility and firepower were

more decisive. 

Arrayed against the UN forces were some 290,000 Chinese and

North Korean soldiers. The Chinese were organized into seven corpssize armies and twenty-two divisions, 204,000 strong, primarily hold5

General Ridgway

(National Archives)
ing the western and central portions of the front. About 52,000

North Korean soldiers, in turn,

organized into three corps and

fourteen understrength divisions,

held the eastern sector. In addition,

an estimated 30,000 North Korean

guerrillas were still behind UN

lines in the mountainous areas of

eastern South Korea. Although the

Chinese had halted their offensive

after heavy casualties, they had no

shortage of manpower. Supply difficulties, rather than casualties, had

stopped the Chinese Communists’

drive south, encouraging American

commanders, in turn, to resume

their own offensive north.

On 20 January 1951, General

Ridgway, Eighth Army commander,

issued a directive designed to convert his current reconnaissance

operations into a deliberate counterattack. Since the enemy situation

was still unclear, the action, codenamed Operation THUNDERBOLT,

was designed to discover enemy

dispositions and intentions with a

show of force. The operation had

the additional objective of dislodging any enemy forces south of the

Han River, the major estuary running southeast from the Yellow Sea

through Seoul and beyond. The projected attacks did not represent a

full-scale offensive. Phase lines—lines drawn on maps with specific

reporting and crossing instructions—would be used to control tightly the

advance of the I and IX Corps. The units were to avoid becoming heavily engaged. To accomplish this, each corps would commit only a single

U.S. division and ROK regiment. This use of terrain-based phase lines

and of limited advances with large forces in reserve was to become the

standard procedure for UN offensive operations for the rest of the war. 

The first, or western, phase of Operation THUNDERBOLT lasted

from 25 to 31 January. The I and IX Corps moved up to twenty miles

6

XXXI IX

I IX

XXX

THUNDERBOLT

 25 Jan–11 Feb

XXX

EIGHT

Iron

Triangle

Sibyon-ni

Ch’orwon

P’yonggang

SEOUL

Inch’on

Uijongbu

Munsan-ni

Kum

P’yongt’aek

Ansong

Masan-ni

Suwon

Yangp’yong

Y Ich’on

Hw

Kimpo

Afld

Ch'

38°
into the area south of Seoul. Only the Turkish Brigade, attached to the

U.S. 25th Infantry Division, east of Osan, a major city twenty miles

south of Seoul, encountered stiff resistance. Elsewhere opposition was

light, and the Chinese merely conducted rearguard actions rather than

hold their ground. On the twenty-sixth, Suwon, north of Osan, with its

large airfield complex, was recaptured. Close air support sorties supported the advance, damaging enemy lines of communications and

pounding points of resistance. 

As January neared its end, Chinese resistance began gradually to

increase, indicating that the main enemy line had almost been reached.

On 27 January the U.S. 3d Infantry Division joined the attack in the I

7

XXX

ROK III ROK I

IX X

XXX

XXX

X ROK III

ROUNDUP

5–11 Feb

IX X

XXX

X

TH

25 Jan

11 Feb

Punchbowl

Yangyang

Hongch’on

hwa

Chip’yong-ni

oju

Wonch’on

Chech’on

Wonju

Ch’ungju

Yongwol

Samch’ok

Ulchin

Hoengsong

Kangnung

Han’gye-ri

Inje

Taep’o-ri

ach’on

unch'on

SEA

O F

JAPAN

HWACH’ON

RESERVOIR

Han

Han R

R

Soyang R

Pukhan R

38°

ELEVATIONS IN METERS

0

10 0 10 20 30 40

10 0 10 20 30

200 500 1000 AND ABOVE

KILOMETERS

MILES

UN COUNTEROFFENSIVE

Phase I

25 January–11 February 1951
Corps sector, and on the twenty-ninth Ridgway converted

THUNDERBOLT into a full-scale offensive with X Corps joining the

offensive on its eastern flank. The I and IX Corps continued a steady,

if slow, advance to the Han River against increasingly more vigorous

enemy defenses. On 2 February armored elements of the X Corps

reached Wonju, located in the central section fifty miles southeast of

Seoul. Other elements of the X Corps recaptured Hoengsong, ten

miles north of Wonju, the same day.

As part of the I Corps attack, the U.S. 25th Infantry Division

advanced against stiff enemy resistance in high ground south of Seoul.

One obstacle, Hill 180, an enemy strongpoint located near Soam-ni,

proved particularly difficult. Capt. Lewis L. Millett of Company E,

27th Infantry, 25th Division, led his company against that hill in a dramatic bayonet and grenade assault. The tank-infantry task force to

which Millett’s company belonged had been held up for several days

by a determined, mixed force of Chinese and North Koreans. In the

resulting hand-to-hand combat, the American shock action carried the

day, routing the enemy from his well-entrenched positions atop the

hill. The surviving defenders fled the battlefield, leaving their equip8

The 96th Field Artillery Battalion winds its way through the mountains 

to the 1st Cavalry Division area, 26 January 1951. (National Archives)
9

ment and weapons behind, while Millett, in the thick of the fighting,

was subsequently awarded the Medal of Honor. 

Actions such as Millett’s sustained the UN offensive despite fierce

Communist resistance. On 9 February the enemy defense opposite I

and IX Corps gave way. Soon UN units in the west were racing northward. The U.S. 25th Infantry Division retook Inch’on and Kimpo

Airfield as elements of I Corps closed on the south bank of the Han

opposite Seoul. 

While the three U.S. corps advanced west and into the center,

General Ridgway decided to expand the offensive to the east by committing additional elements of the X Corps and the ROK III Corps

(under X Corps control) in an operation code-named ROUNDUP.

ROUNDUP’s object was the expansion of the offensive to the central

sector of the front. The X Corps’ ROK 5th and 8th Divisions were to

retake Hongch’on, fifteen miles north of Hoengsong, and in the

process destroy the North Korean forces in that vicinity. U.S. forces

supporting the movement included the 2d and 7th Infantry Divisions

and the 187th Airborne Regimental Combat Team (RCT). ROUNDUP

would also protect the right flank of THUNDERBOLT. Farther east, the

ROK III Corps, on X Corps’ right flank and still under its control,

would also advance north. The operation commenced on 5 February,

with both the X and the ROK III Corps attacking steadily, but against

increasing enemy resistance. 

While UN forces in Operation THUNDERBOLT advanced to an area

just south of the Han against only minor resistance, Chinese and North

Korean forces were massing in the central sector north of Hoengsong

seeking to renew their offensive south. On the night of 11–12 February

the enemy struck with five Chinese People’s Liberation Army (PLA)

armies and two North Korean corps, totaling approximately 135,000

soldiers. The main effort was against X Corps’ ROK divisions north of

Hoengsong. The Chinese attack, dramatically announced with bugle

calls and drum beating, penetrated the ROK line and forced the South

Koreans into a ragged withdrawal to the southeast via snow-covered

passes in the rugged mountains. The ROK units, particularly the 8th

Division, were badly battered in the process, creating large holes in the

UN defenses. Accordingly, UN forces were soon in a general withdrawal to the south in the central section, giving up most of the terrain

recently regained. Despite an attempt to form a solid defensive line,

Hoengsong itself was abandoned on 13 February. 

Also on the thirteenth the Chinese broadened the offensive against

the X Corps with attacks against U.S. 2d Infantry Division positions

near Chip’yong-ni, on the left of the corps’ front. They also struck far-
ther to the west out of a bridgehead south of the Han near Yangp’yong

against elements of the U.S. 24th Infantry Division, holding the IX

Corps’ right flank. The 21st Infantry of the 24th Division quickly contained the Yangp’yong attack that was aimed toward Suwon, but at

Chip’yong-ni the Chinese encircled the 2d Division’s 23d Infantry and

its attached French Army battalion, cleverly exploiting a gap in the

overextended American lines. 

Chip’yong-ni was a key road junction surrounded by a ring of

small hills. Rather than have the 23d Infantry withdraw, General

Ridgway directed that the position be held to block or delay Chinese

access to the nearby Han River Valley. An enemy advance down the

east bank of the Han would threaten the positions of the IX and I

Corps west of the river. Accordingly, the UN forces at Chip’yong-ni

dug into the surrounding hills and formed a solid perimeter while reinforcements were mustered. The role of the Air Force was essential at

Chip’yong-ni with close air support forcing the attackers to conduct

their assaults only after dark. And once the enemy had cut off the

ground routes, all resupply was by air. 

As Ridgway hoped, the 5,000 defenders of Chip’yong-ni quickly

became the focus of Chinese attention. Throughout the night of 13–14

10

IX X

XXX

XXX

X ROK III

18 Feb

11 Feb

XXXX

PLA 66

XXXX

PLA 39

XXXX

PLA 42

XXXX

PLA 40

XXX

NK II

XXX

NK V

X

BRIT 27

XX

1

XX

24

XX

7

XX

2

XX

ROK 5

XX

ROK 3

XX

ROK 6

XX

ROK 8

XX

ROK 7

XX

ROK 9

III

2 23

III

187

Hongch’on

Chip’yong-ni

Yoju

Wonch’on

Chech’on

Wonju

Yongwol

Hoengsong

Ch'unch'on

Han

Han R

R

ELEVATIONS IN METERS

0

10 0 10 20 30

10 0 10 20

200 500 1000 AND ABOVE

KILOMETERS

MILES

CCF COUNTERATTACK

11–18 February 1951
February, three Chinese divisions assaulted the perimeter, supported

by artillery. The attackers shifted to different sections of the two-mile

American perimeter probing for weak points. The Chinese were often

stopped only at the barbed wire protecting the individual American

positions, with the defenders employing extensive artillery support

and automatic weapons fire from an attached antiaircraft artillery battalion. Daylight brought a respite to the attacks. True to form, the

Chinese renewed their assaults the night of 14–15 February. Again the

fighting was intense. During the 14 February attack, Sfc. William

Sitman, a machine gun section leader in Company M, 23d Infantry,

was posthumously awarded the Medal of Honor for his actions in providing support to an infantry company, in the end placing his body

between an enemy grenade and five fellow soldiers.

While the 23d Infantry held on at Chip’yong-ni, the situation to

the southeast was grave. At the time Ridgway and Maj. Gen. Edward

M. Almond, the X Corps commander, were seeking to stabilize the

front line between Chip’yong-ni and Wonju, where the destruction of

the ROK forces around Hoengsong had created major gaps in the

defensive line. For three desperate days, the front wavered as the

Chinese attempted to exploit these gaps before UN reinforcements

could arrive on the scene. Ridgway acted quickly to push units into the

critical areas, ordering IX Corps to move the 27th British

Commonwealth Brigade and the ROK 6th Division over to X Corps

and into the gap south of Chip’yong-ni. The action proved timely. On

the night of 13–14 February, the Chinese conducted major assaults at

Chip’yong-ni, Ch’uam-ni, five miles southeast of Chip’yong-ni, and at

Wonju. But supported by massed artillery and air support, the UN

forces repulsed the attacks, causing heavy Chinese casualties. 

To provide additional support, the IX Corps, commanded by Maj.

Gen. Bryant E. Moore, now began directly assisting the X Corps in

restoring the front and relieving Chip’yong-ni. On 14 February the 5th

Cavalry, detached from the U.S. 1st Cavalry Division, was taken out of

IX Corps reserve and assigned the relief mission. For the task, the

three infantry battalions of the 5th Cavalry were reinforced with two

field artillery battalions, two tank companies, and a company each of

combat engineers and medics. Initially the relief force advanced rapidly, making half the twelve-mile distance to Chip’yong-ni from the

main U.S. defensive line on the first day. Damaged bridges and roadblocks then slowed movement. On the morning of the fifteenth, two of

the infantry battalions assaulted enemy positions on the high ground

north of the secondary road leading to Chip’yong-ni. When the attack

stalled against firm Chinese resistance, Col. Marcel Crombez, 5th

11
Cavalry commander, organized a force of twenty-three tanks, with

infantry and engineers riding on them, to cut through the final six

miles to the 23d Infantry. The tank-infantry force advanced in the late

afternoon, using mobility and firepower to run a gauntlet of enemy

defenses. Poor coordination between the tanks and supporting artillery

made progress slow. Nevertheless, in an hour and fifteen minutes the

task force reached the encircled garrison and spent the night there. At

daylight the tanks returned to the main body of the relief force unopposed and came back to Chip’yong-ni spearheading a supply column.

With the defenders resupplied and linked up with friendly forces, the

siege could be considered over. UN casualties totaled 404, including

52 soldiers killed. Chinese losses were far greater. Captured documents later revealed that the enemy suffered at least 5,000 casualties.

The defense of Chip’yong-ni was a major factor in the successful

blunting of the Chinese counteroffensive in February 1951 and a major

boost to UN morale.

Elsewhere on 15 February, the efforts to restore the front finally

bore fruit. Rather than take advantage of the weakened front to the

east, the Chinese had chosen to concentrate on eliminating the U.S.

forces at Chip’yong-ni first. But they had chosen poorly, and the

respite allowed Moore and Almond to restore their lines.

Reinforcements, particularly the U.S. 7th Infantry Division and 187th

Airborne RCT, helped the South Koreans form a solid line around

Wonju and near Chech’on, twenty miles to the southwest. By the eighteenth the Communist offensive was spent, and enemy forces began

withdrawing to the north rather than attempting to hold what they had

taken. Such tactics would become the familiar way that the

Communists would indicate the end of their offensives. Heavy casualties and the need for resupply and reorganization frequently forced the

Chinese to break direct contact and pull back. UN firepower was simply too strong. 

With the enemy withdrawing, Ridgway immediately ordered an

advance by the IX Corps, while the X Corps moved to destroy the

Communist forces around Chech’on in the central sector. By the nineteenth the initiative had completely shifted back to the United Nations

Command. The new offensive became formalized on 20 February as

Operation KILLER. Ridgway hoped that the name would help encourage an offensive spirit in the Eighth Army. The IX, X, and ROK III

Corps were directed north toward a line, named Arizona, running from

Yangp’yong east to positions north of Hoengsong and along the eastwest portion of the Wonju-Kangnung highway, all about twelve to fifteen miles above the current front line. The operation was designed to

12
enhance the damage to enemy forces and in practice proved methodical, often slowed by the spring thaw and heavy rains that swelled

streams and turned roads into seas of mud. By 28 February all units

had reached their KILLER objectives, in the process finally eliminating

all enemy forces south of the Han River. Nevertheless, many enemy

units escaped by withdrawing north under cover of inclement weather. 

With General MacArthur’s support, Ridgway planned a new operation, code-named RIPPER, to continue the advance twenty to thirty

miles northward to a new line, Idaho. Line Idaho was in an arc with its

apex just south of the 38th Parallel. The major objectives of RIPPER

included the recapture of Seoul and of the towns of Hongch’on, fifty

miles west of Seoul, and Ch’unch’on, fifteen miles farther to the north.

However, the destruction of enemy forces continued to be more important than geographical objectives. Although the removal of all

Communist forces from areas south of the 38th Parallel and the

restoration of South Korea’s prewar boundaries remained a broad

strategic objective, weakening the enemy’s military power was the primary operational goal. 

13

M4 tanks of the 89th Tank Battalion, 25th Infantry Division, cross the 

Han River, 7 March 1951. (National Archives)
RIPPER commenced on 7 March with the I and IX Corps on the west

near Seoul and Hoengsong and X and ROK III Corps in the east. One of

the largest UN artillery bombardments of the war preceded the offensive. On the left, the U.S. 25th Infantry Division quickly crossed the Han

and established a bridgehead. Farther to the east, IX Corps reached its

first phase line on 11 March. Three days later the advance proceeded to

the next phase line. During the night of 14–15 March, elements of the

ROK 1st Division and U.S. 3d Infantry Division liberated Seoul. The

capital city changed hands for the fourth and last time in the war. The

Communist forces were compelled to abandon it when the UN approach

to the east of the city threatened the defenders with encirclement. 

14

I IX

XXX

KILLER

20 Feb–6 Ma

RIPPER

6–31 Mar

COURAGEOUS

22–28 Mar

RUGGED/DAUNTLESS

1–22 Apr

IX X

XXX

XXXX

EIGHTH

Iron

Triangle

Punchbowl

Sibyon-ni

Ch’orwon

P’yonggang

Hongch’on

SEOUL

Inch’on

Uijongbu

Munsan-ni

Kumhwa

P’yongt’aek Ansong

Masan-ni

Suwon

Yangp’yong Chip’yong-ni

Yoju

Wonch’on

Chech’on

Wonju

Ch’ungju

Hoengsong

Han’gye-ri

Inje Hwach’on

Kimpo

Afld

Ch'unch'on

HWACH’ON

RESERVOIR

Han R

Soyang R

Puk hanR

38°

ELEVATIONS IN METERS

0

10 0 10 20 30 40

10 0 10 20 30

200 500 1000 AND ABOVE

KILOMETERS

MILES

UN COUNTEROFFENSIVE

Phase II

20 February–22 April 1951

Drop Zone, 23 May
Following the recapture of

Seoul, Communist forces retreated

northward, conducting skillful

delaying actions that utilized the

rugged, muddy terrain to maximum advantage, particularly in the

mountainous X Corps sector.

Despite such obstacles, RIPPER

pressed on throughout March. In

the mountainous central region, the

IX and X Corps pushed forward

methodically, the IX Corps against

light opposition and the X Corps

against staunch enemy defenses.

Hongch’on was taken on the fifteenth and Ch’unch’on secured on

the twenty-second. The capture of

Ch’unch’on was the last major

ground objective of Operation

RIPPER. UN forces had advanced

north an average of thirty miles

from their start lines. However,

while the Eighth Army units had

occupied their principal geographic objectives, the goal of destroying enemy forces and equipment

had again proved elusive. More

often than not, the enemy withdrew

before he could receive extensive

damage. Ch’unch’on, a major

Communist supply hub, was empty

by the time UN forces finally occupied it. 

Even with RIPPER in its final stages, Ridgway’s staff was planning

a new operation. Code-named COURAGEOUS, it was designed to trap

large Chinese and North Korean forces in the area between the Han

and Imjin Rivers north of Seoul, opposite I Corps. The operation featured a parachute drop by the 187th Airborne RCT onto the south

bank of the Imjin River near Munsan-ni, twenty miles north of the current front line, and a rapid advance by an armored task force. Both the

airborne drop, which used over a hundred C–119 Flying Boxcar transport aircraft, and the armored movement were successfully executed.

The drop took place on 22 March, and Task Force Growdon (made up

15

XXX

ROK III ROK I

XXX

X ROK III

ar

20 Feb

Yangyang

Yongwol

Samch’ok

Ulchin

Kangnung

Taep’o-ri

SEA

O F

JAPAN

Han R

38°
of armored elements from the U.S. 24th Infantry Division’s 6th

Medium Tank Battalion, borrowed from IX Corps, and infantry elements from the U.S. 3d Infantry Division) linked up with the paratroopers on the twenty-third. The 187th faced only weak resistance,

and the armored task force faced primarily minefields rather than

active defenses. However, once again Communist forces withdrew

more rapidly than the UN forces could advance to trap them. 

As March 1951 drew to a close Eighth Army units were nearing

the 38th Parallel. However, with indications that the Chinese and

North Koreans were massing forces for a spring offensive, Ridgway

decided to move even farther north to secure more defensible positions. President Harry S. Truman and General MacArthur agreed.

The new advance was divided into two sub-operations code-named

RUGGED and DAUNTLESS. The first, Operation RUGGED, was designed

to secure a new line, Kansas, just north of the 38th Parallel. The second, Operation DAUNTLESS, would see the UN forces continue twenty miles farther to the north to another line, designated Wyoming.

Wyoming would then be transformed into a heavily defended outpost

line. When the Communists opened their next offensive, the forces

along Wyoming were to conduct a fighting withdrawal south to Line

Kansas, while causing the maximum amount of casualties and dis16

Chinese prisoners captured north of the Imjin River by the 

1st Cavalry Division (National Archives)
ruption to the enemy. The main defensive battle would then be

fought along Kansas. Ridgway also intended DAUNTLESS to threaten

the enemy logistical hub located in a region nicknamed the Iron

Triangle, northwest of Kumhwa, a crossroads town twenty miles

north of Line Kansas. 

The two-phase operation began on 1 April, with the I and IX

Corps in the west and the ROK I Corps in the east reaching Line

Kansas by the fifth. In the center, the X and ROK III Corps were also

closing in on the line after a late start. Then the I and IX Corps

moved forward toward Ch’orwon, southwest of the Iron Triangle, and

reached an intermediate phase line, Utah, by the eleventh. To their

right, X Corps forces took a dam overlooking the Hwach’on

Reservoir five days later. On 20 April, the last UN forces, the U.S. 7th

Infantry Division and the ROK 3d Division of the X Corps, reached

Line Kansas. Final preparations began to continue the advance to

Line Wyoming. However, all UN offensive action ceased when

Communist forces launched their spring offensive across the entire

front on 22 April. 

During Operation RUGGED turbulence at the higher American

command levels led to significant leadership changes in the Far East

Command and the Eighth Army. On 10 April, as the result of a disagreement over strategy, President Truman relieved General

MacArthur as Commander in Chief, U.S. Far East Command, replacing him with General Ridgway. Four days later, Lt. Gen. James A. Van

Fleet, in turn, replaced Ridgway as Eighth Army commander.

MacArthur had long chafed at the limitations imposed on him, especially those restricting direct action against the People’s Republic of

China. In March he expressed his views in a letter to Congressman

Joseph Martin of Massachusetts, who made the letter public in early

April. Truman saw the action as just one more example of

MacArthur’s attempts to defy his authority as Commander in Chief.

Accordingly, after consulting with selected members of his cabinet

and the Joint Chiefs of Staff, the president removed the venerable and

popular World War II general. This action created a political firestorm

in the United States, but its impact on battlefield operations, other than

the change at the highest levels of command, was minimal. 

The new offensive was the Chinese’s fifth of the war. At the time,

UN forces were astride or slightly north of Line Kansas, which extended 116 miles from the confluence of the Han and Imjin Rivers on the

west, following the Imjin northeast to the 38th Parallel, then generally

following the parallel easterly along good defensive terrain to the Sea

of Japan. The lead units of the I and IX Corps had advanced forward

17
of Kansas to Line Utah, well on their way to Line Wyoming. Both

corps took the brunt of the offensive conducted by three Chinese army

groups (called fronts by the Chinese) and a North Korean corps converging from the north and northwest and aiming for the northeastsouthwest corridor leading fifty miles down to Seoul (the Yonch’onUijongbu-Seoul corridor).

The offensive actually began in the center of the UN line during

the night of 21–22 April with a Chinese assault on the ROK 6th

Division west of the Hwach’on Reservoir. The weight of the enemy

attack broke through the division, exposing the flanks of the adjacent

U.S. 24th Infantry Division in the X Corps sector to the west and the

18

I IX

XXX

IX X

XXX

XXXX

EIGHTH

XXX

NK

XXX

NK I

XXX

NK III

XXXX

PLA 19

XXXX

PLA 3

XXXX

PLA 9

XXXX

PLA 13

30 Apr

XXXX

XXXX PLA 12

PLA 60

XXXX

PLA 26

XXXX

PLA 15

XXXX

PLA 27

XX

N

Iron

Triangle

Punchbowl

Sibyon-ni

Ch’orwon

P’yonggang

Hongch’on

SEOUL

Inch’on

Uijongbu

Munsan-ni

Kumhwa

P’yongt’aek Ansong

Masan-ni

Suwon

Yangp’yong Chip’yong-ni

Yoju Ich’on

Wonch’on

Chech’on

Wonju

Ch’ungju

Yongw

Hoengsong

Han’gye-ri

Inje Hwach’on

Kimpo

Afld

Ch'unch'on

HWACH’ON

RESERVOIR

Han R

Soyang R

Pukhan R

38°

ELEVATIONS IN METERS

0

10 0 10 20 30 40

10 0 10 20 30

200 500 1000 AND ABOVE

KILOMETERS

MILES

CHINESE SPRING OFFENSIVE

22 April–20 May 1951
U.S. 1st Marine Division to the

east. A follow-on Chinese push the

next day completed the collapse of

the ROK 6th and advanced south

of Kap’yong, twenty miles southwest of the reservoir. There elements of the British 27th Brigade

and the attached U.S. 72d Tank

Battalion finally held off the

attacking Chinese forces, enabling

an orderly UN withdrawal. For this

action Company A, 72d Tank

Battalion, and the Australian and

Canadian battalions of the British

brigade were later awarded the

Presidential Unit Citation. 

In the I Corps sector, the 24th

Division and the Turkish Brigade

bore the direct impact of the

Chinese main effort. The I and IX

Corps immediately began withdrawing southward to prepared

positions along Line Kansas.

These objectives were reached the

next day. Also in the I Corps,

multinational UN forces from

Belgium, the Philippines, the

United Kingdom, and the United

States were fighting a series of

intense battles as the enemy

crossed the Imjin River and established bridgeheads on the southern bank. By the twenty-third most I

and IX Corps units were back on Line Kansas.

Also on 23 April the Chinese offensive expanded to the east and

east-central areas. A successful North Korean advance against the

ROK 5th Division in the center, on the right flank of the X Corps,

enabled the enemy to move below Line Kansas and Inje, the major

town located in the west halfway between the Hwach’on Reservoir and

the Sea of Japan. Along the Imjin, the Chinese penetrated between the

positions of the ROK 1st Division and the British 29th Brigade in the I

Corps sector. Enemy forces then surrounded the 29th Brigade’s

Gloucestershire Battalion on a hilltop near Solma-ri, several miles

19

XXX

ROK III ROK I

20 May

XXX

X ROK III

V

22 Apr

X

NK II

Yangyang

ol

Samch’ok

Ulchin

Kangnung

Taep’o-ri

SEA

O F

JAPAN

Han R

38°
20

south of the Imjin. The Gloucesters put up a heroic defense, which

later won them a U.S. Presidential Unit Citation. When relief attempts

failed to reach the battalion and an early breakout effort collapsed on

the twenty-fourth and twenty-fifth, the battalion attempted to break out

on its own and was destroyed, with most of its surviving members captured. The inability of I Corps to extract the Gloucestershire Battalion

was due to a combination of factors: poor decisions, unreliable communications, rough terrain, and determined enemy resistance. The cost

was heavy: 20 British soldiers killed, 35 wounded, and 575 missing in

action and presumed captured. 

Despite the extensive use of air strikes and massed artillery, the

multiple enemy penetrations destroyed Eighth Army hopes of establishing a firm defensive line along Kansas. On 25 April Maj. Gen.

Frank W. Milburn, the I Corps commander, ordered a further withdrawal to a new line, Delta, located roughly ten miles south of Kansas,

and a subsequent fall back to a line closer to Seoul designated

Golden. It was now obvious that the objective of the Chinese offensive

was nothing less than the recapture of Seoul. The withdrawal of I

Corps forced Van Fleet to move the rest of the Eighth Army back all

across its front. He hurriedly created a new line as an extension of

Golden across the whole peninsula, which he ironically named the No

Name line. 

The fighting during the Chinese spring offensive was again extremely bitter. In the three-day period of 24–26 April 1951 alone, six

American soldiers earned Medals of Honor, including four awarded to

members of the 7th Infantry, 3d Infantry Division. Three were posthumous: Cpl. John Essebagger, Company A; Pfc. Charles L. Gilliland,

Company I; and Cpl. Clair Goodblood, Company D. Cpl. Hiroshi

Miyamura of Company H also earned the medal. All four distinguished

themselves with exceptional gallantry in separate defensive actions

against large assaulting enemy forces, inflicting disproportionately

heavy casualties on the attackers. 

The Eighth Army completed its withdrawal to the No Name line

by 28 April. Although torrential rainstorms slowed the maneuver, they

hindered the Chinese advance as well. The new defenses were sited on

good terrain and held. Once the Chinese attack was spent, UN forces

limited their activities to patrolling and local counterattacks. The

Communists had failed to recapture Seoul and, with UN forces in

good defensible positions, any renewed offensive would face even less

chance of succeeding. 

The new Eighth Army line extended from the Han estuary east in

an arc six miles north of Seoul and then continued east along the Han
The 65th Infantry, 3d Infantry Division, withdraws to Line Utah; 

below, escorting a wounded 25th Division infantryman down the 

hill to an aid station, 2 April 1951. (National Archives)
for twenty miles to the town of Tokso-ri, then northeast across the

peninsula to Taep’o-ri, a port on the east coast. On 30 April, fearing a

new Communist effort to take Seoul, General Van Fleet started shifting forces westward, shoring up the area around the capital. This left a

primarily ROK force in the mountainous sectors of the X and ROK III

Corps. He also fortified the line as much as possible. While Eighth

Army units improved their positions over the next week, the front was

quiet, with little contact between opposing forces. Van Fleet, taking

advantage of the lull, issued instructions for the Eighth Army to

advance forty miles back to Line Kansas. On 9 May UN forces made

22

I IX

XXX

IX X

XXX

XXXX

EIGHTH

8 Jul

KANSAS

Iron

Triangle

Punchbowl

Sibyon-ni

Ch’orwon

P’yonggang

Hongch’on

SEOUL

Inch’on

Uijongbu

Munsan-ni

Kumhwa

P’yongt’aek Ansong

Masan-ni

Suwon

Yangp’yong Chip’yong-ni

Yoju Ich’on

Wonch’on

Chech’on

Wonju

Ch’ungju

Yongw

Hoengsong

Han’gye-ri

Inje Hwach’on

Kimpo

Afld

Ch'unch'on

HWACH’ON

RESERVOIR

Han R

Soyang R

Pukhan R

38°

ELEVATIONS IN METERS

0

10 0 10 20 30 40

10 0 10 20 30

200 500 1000 AND ABOVE

KILOMETERS

MILES

UN SPRING OFFENSIVE

22 May–8 July 1951
limited attacks north, while intensifying preparations for yet another

major offensive slated to begin on

the twelfth. But on the eleventh,

intelligence indicated that the

enemy was once again ready to

renew his own offensive, and all

UN attack planning was halted. 

The Chinese Communists’

renewed offensive began on 16 May.

This time the enemy struck the eastern portion of the front, along the

boundary between the X Corps and

ROK III Corps. The Chinese had

shifted five armies eastward

between 10 and 16 May, and the

attack came across the Soyang River

against four ROK divisions. The

ROK 5th and 7th Divisions, under

X Corps control, were withdrawn

southward in a matter of hours.

However, the ROK III Corps failed

to extract its two threatened units,

the ROK 3d and 9th Divisions, and

the Chinese quickly destroyed both

and poured through the resulting

gap. The enemy advanced as far as

Soksa-ri, thirty-five miles south of

the original front. 

West of the breakthrough the X

Corps’ U.S. 2d Infantry Division

attempted to stem the Chinese tide.

In addition to facing fierce enemy attacks to its front, the division had

to contend with the collapse of the ROK units on its right flank. But

despite heavy losses, the division held its ground. Meanwhile, Van

Fleet rushed the U.S. 3d Infantry Division to the X Corps from Seoul

to cover the ROK III Corps’ withdrawal. Reassuringly, in the east the

ROK I Corps continued to conduct an orderly retreat to a new line

along the main east-west Kangnung–Soksa-ri road.

The combination of the stiff resistance of units such as the U.S. 2d

Infantry Division, the orderly withdrawal of the ROK forces in the east,

and the shifting of reinforcements stopped the Communist advance. As

23

XXX

X ROK I

20 May

Yangyang

ol

Samch’ok

Ulchin

Kangnung

Taep’o-ri

SEA

O F

JAPAN

Han R

38°
24

in all previous Chinese offensives, the attack lost its impetus after a couple of days when the combination of heavy casualties and poor resupply

caught up with the Communist troops. In typical fashion, the enemy fell

back to regroup, allowing the UN front to stabilize. Unknown to the

defenders, this was to be the last major Chinese offensive of the war. 

Unwilling to give the enemy a chance to reorganize for another

attack, Van Fleet directed the Eighth Army to shift immediately onto

the offensive. Once again the goal was to regain the better defensive

positions of Line Kansas slightly north of the 38th Parallel. The new

UN advance was also designed to exact maximum enemy casualties

and, hopefully, destroy or cut off major enemy units. The counteroffensive quickly secured positions along key road networks in the central area around the towns of Hwach’on and Inje, inflicting heavy

casualties in the process. Inje and Hwach’on were back in Eighth

Army hands by 27 May, and escape routes south of the Hwach’on

Reservoir were severed. However, mud, rain, and effective Chinese

delaying actions impeded efforts to close all of the escape routes, precluding the complete destruction of enemy forces and supply bases. 

On 1 June Secretary of State Dean Acheson indicated U.S. willingness to accept a cease-fire line in the vicinity of the 38th Parallel.

Engineers probe for enemy mines ahead of a creeping tank south 

of Ch’orwon, 10 June 1951. (National Archives)
25

At the time UN forces were again at, or slightly north of, the parallel.

The secretary of state’s feeler expressed a policy espoused earlier in

May by President Truman, which in turn imposed definite limitations

on the Eighth Army’s advance. Once UN forces reached the defensible

positions of Line Kansas and its outpost Line Wyoming, the attack

north would stop and measures would be taken to fortify the front. On

11 June the U.S. 3d Infantry Division, in the I Corps zone, captured

Ch’orwon on Line Wyoming south of the Iron Triangle. By the fifteenth UN forces had closed on Line Kansas everywhere, while in the

west the I and IX Corps had moved in force to Line Wyoming, securing the lateral road running east-west between Ch’orwon and

Kumhwa, fifteen miles to the east.

For the rest of June, UN forces continued to improve their defensive

positions, heavily fortifying Line Kansas. Meanwhile the Air Force,

with mixed success, executed Operation STRANGLE, a massive effort to

interdict Communist supply routes by air. The UN line was anchored in

the west along the Han estuary just south of the 38th Parallel. From

there it extended to the northeast south of the Iron Triangle, curved

around the UN-controlled Hwach’on Reservoir, and then rose steeply

north to meet the Sea of Japan on the east coast forty-two miles north of

the parallel. With minor modifications, this front became the cease-fire

line agreed to in 1953 and is still in place a half-century later. 

On 23 June the Soviet ambassador to the UN called for cease-fire

negotiations. As the real possibility of negotiations loomed, Eighth

Army forces continued to improve their positions, building strongpoints and conducting active patrolling. Since April the enemy had

suffered more than 200,000 casualties and heavy losses in equipment,

drastically impairing his ability to conduct large-scale offensive operations. On 2 July the Chinese and North Koreans finally agreed to

cease-fire negotiations. The parties agreed on the choice of Kaesong, a

village north of the front line in the eastern sector, as the site for the

talks, and the meetings formally began in early July. The negotiations

marked the end to major offensives conducted by both sides. However,

both the talks and the fighting would continue for two long years, with

the war characterized by small-scale infantry battles to gain control of

hilltops and other tactically critical pieces of terrain. Despite peace

talks, the war was not yet over.

Analysis

The winter and spring campaigns of 1951 are a bridge between the

mobile battles of 1950 and the static warfare that marked the last two
years of the war. The defeat of the Communist advance into South

Korea and the restoration of a firm defensive line roughly along the

38th Parallel decided the outcome of the war and guaranteed the future

of South Korea. U.S. and UN resolve in the subsequent summer fighting brought the Chinese and North Koreans to the peace table. The

American response to the shock of the Chinese intervention evolved

into a firm determination to limit the objectives of the war to the continued existence of South Korea. There would be no reconquest of

North Korea or any widening of the war. This strategic shift led to the

dismissal of its principal opponent, General of the Army Douglas

MacArthur. Wars and operations with limited strategic objectives have

been a feature of American global strategy ever since. 

The concept of limited war affected the Army in many ways. In

April 1951 the United States armed forces adopted an individual rotation policy. American soldiers were no longer expected to remain in

the theater of operations for the duration of the conflict but would now

be rotated back to the United States after a specific period of time,

roughly a year. U.S. forces would subsequently follow a similar rotation policy in Vietnam. Theater commanders could expect only a limited number of reinforcements and replacements, with inadequate

training and personnel turbulence becoming familiar problems as

experienced personnel steadily returned to the United States. 

Tactically, UN forces had proved able to handle the Chinese and

North Koreans on their own terms. After restoring the front line near

the original 38th Parallel demarcation line, despite some perilous

moments, the UN halted rather promptly the massive CCF spring

offensive and quickly regained the lost ground. Although the enemy

often took advantage of the hastily organized and equipped ROK divisions, those units improved considerably by mid-1951. UN commanders had learned how to deal with the Chinese style of warfare—characterized by furious offensive operations, only marginally sustained,

followed by withdrawal and regrouping. Failed offensives convinced

the Communists that the conquest of South Korea was no longer possible under the existing conditions and made the cease-fire table an

appealing option. 

26
Further Readings

Appleman, Roy C. Ridgway Duels for Korea. College Station: Texas

A&M University Press, 1990. 

Blair, Clay. The Forgotten War: America in Korea, 1950–53. New

York: Time Books, 1988. 

Fehrenbach, T. R. This Kind of War: A Study in Unpreparedness. New

York: Macmillan, 1963. 

Mossman, Billy C. Ebb and Flow: November 1950–July 1951. United

States Army in the Korean War. Washington, D.C.: U.S. Army

Center of Military History, 1990. 

Schnabel, James. Policy and Direction: The First Year. United States

Army in the Korean War. Washington, D.C.: U.S. Army Center of

Military History, 1972.

27
CMH Pub 19–9

Cover: 3d Division infantrymen climb the trail to their objective near

Uijongbu, 23 March 1951. (National Archives)

PIN : 078426–000