Battle of the Pusan Perimeter

North Korean troops, hampered by supply shortages and massive losses, continually staged attacks on UN forces in an attempt to penetrate the perimeter and collapse the line.

Elements of the 3rd Battalion, 29th Infantry Regiment, newly arrived in the country, were wiped out at Hadong in a coordinated ambush by KPA forces on July 27, leaving open a pass to the Busan area.

[14][15] The KPA was organized into a mechanized combined arms force of ten divisions, originally numbering some 90,000 well-trained and well-equipped troops in July, with hundreds of T-34 tanks.

[16] However, defensive actions by US and ROK forces had delayed the KPA significantly in their invasion of South Korea, costing them 58,000 of their troops and a large number of tanks.

[36]On July 1, the US Far East Command directed the Eighth Army to assume responsibility for all logistical support of the US and UN forces in Korea,[37] including the ROKA.

[45] The consumption of aviation gasoline thanks to both combat and transport aircraft was so great in the early phase of the war, taxing the very limited supply available in the Far East, that it became one of the serious logistical problems.

[49] North Korea's lack of large airstrips and aircraft meant it conducted only minimal air resupply, mostly critical items being imported from China.

[51][52] In mid-July, the UN Far East Air Force Bomber Command began a steady and increasing campaign against strategic North Korean logistics targets.

[49] The KPA's communications and supply were not capable of exploiting a breakthrough and of supporting a continuing attack in the face of massive air, armor, and artillery fire that could be concentrated against its troops at critical points.

[62] On August 1, the Eighth Army issued an operational directive to all UN ground forces in Korea for their planned withdrawal east of the Naktong River.

It would kick off with an attack by the US reserve units on the Masan area to secure Chinju, followed by a larger general push to the Geum River in the middle of the month.

[76] The plan of attack required the force to move west from positions held near Masan, seize the Chinju Pass, and secure the line as far as the Nam River.

[87] Both KPA and American armor swarmed to the scene and US Marine aircraft continued to provide cover, but neither side was able to make appreciable gains despite inflicting massive numbers of casualties on one another.

[71][97] On the night of August 5–6, 800 KPA soldiers began wading across the river at the Ohang ferry site, 3.5 miles (5.6 km) south of Pugong-ni and west of Yongsan, carrying light weapons and supplies over their heads or on rafts.

[101] Despite American counterattacks, the KPA were able to continue pressing forward and take Cloverleaf Hill and Oblong-ni Ridge, critical terrain astride the main road in the bulge area.

The division would sail 20 miles (32 km) south to Yongil Bay to join the other UN forces in a coordinated attack to push the KPA out of the region.

[113] Right at the center of the Busan Perimeter, Daegu stood at the entrance to the Naktong River valley, an area where KPA forces could advance in large numbers in close support.

The division reassembled to the east and launched a concerted night attack, broke the ROK defenses, and began an advance that carried it twenty miles (32 km) southeast of Naktong-ni on the main road to Taegu.

[135] On August 14, General MacArthur ordered the carpet bombing of a 27-square-mile (70 km2) rectangular area on the west side of the Naktong River opposite the ROK 1st Division.

[137][138] The attack required the entire FEAF bombing component, and comprised the largest USAF operation since the Battle of Normandy in World War II.

[140] The UN ground and air commanders opposed future massive carpet bombing attacks unless there was precise information on an enemy concentration and the situation was critical.

[144] Fed by intelligence from the Soviet Union, the North Koreans were aware the UN forces were building up along the Pusan Perimeter and that they had to conduct an offensive soon or else forfeit the battle.

[151] The attacks were to closely connect in order to overwhelm UN troops at each point simultaneously, forcing breakthroughs in multiple places that the UN would be unable to reinforce.

[155] UN troops were looking ahead to Operation Chromite, their amphibious assault far behind North Korean lines at the port of Inchon on September 15, and did not anticipate the KPA would mount a serious offensive before then.

[160] The KPA were initially successful in breaking through UN lines in multiple places and made substantial gains in surrounding and pushing back UN units.

One Indian Armed Forces officer was also killed in the incident, Colonel Manakampat Kesavan Unni Nayar, a representative from the United Nations Commission on Korea.

[189] With the addition of the 5,690 killed in the Bowling Alley, 3,500 at the Naktong Bulge,[105] at least 3,700 at Daegu[135][190][191] and an unknown number at P'ohang-dong before September 1, KPA casualties likely topped 50,000 to 60,000 by the end of the battle.

[201][202]Shortly before the Pusan Perimeter fighting, retreating 1st Cavalry Division troops and U.S. warplanes killed an estimated 250-300 South Korean civilians, mostly women and children, in the No Gun Ri massacre.

[207] With virtually no equipment, exhausted manpower and low morale, the KPA were at a severe disadvantage and were not able to continue to pressure on the Pusan Perimeter while attempting to repel the landings at Inchon.

[211] This would eventually result in Chinese intervention once the UN troops approached the Yalu River, and what was originally known as the "Home By Christmas Offensive" turned into a war that would continue for another two-and-a-half years.

A map showing successive North Korean advance. The Pusan Perimeter is the border of the green portion of the peninsula.
Troops unload supplies from a boat at a pier
UN troops unload in Korea
A crane hoisting a tank into a boat
An M4 Sherman tank being loaded onto a barge at the port of Oakland, California , prior to shipment to Pusan, 1950.
A train being racked by explosions
US aircraft attack a North Korean train with rockets and napalm , 1950.
A road and railway running through mountains
The main Seoul-Busan railway and road was integral in bringing supplies to the front
A man of a defensive perimeter along the southeastern edge of a landmass
Map of the Busan Perimeter, August 1950.
A mountain range in the distance, with one peak prominent
Saddle Ridge near Daegu, one of the positions along Busan Perimeter defended by the UN.
Men in trucks driving down a road
Troops of the 24th Infantry move to the Masan battleground
A tank advances up a hill followed by men in military uniform
US armor advances west of Masan
Two men in military uniforms sitting on a ledge overlooking a river
US Marines sit on a newly captured position overlooking the Naktong River, August 19
Medics treat a pair of injured men in a tent in the middle of a jungle
US Navy Corpsman treats US Marine casualty from the front line of the battle, August 17.
A map showing troops moving north and destroying opposing formations there
South Korean units push North Korean forces northward after intense fighting, August 11–20.
a group of men carry an injured man on a stretcher through a grass field
Marines carrying a wounded man in a stretcher in August 1950.
Lines of troops marching along a road
ROK troops advance to the front lines near P'ohang-dong
A large artillery piece fires as several soldiers look on
US artillery near Waegwan fires at North Korean troops attempting to cross the Naktong River
Bombs explode over a large area of land
US Air Force post-strike picture of a 3.5-by-7.5-mile (5.6 by 12.1 km) area near Waegwan, in which 99 bombers dropped 3,500 500 lb bombs
A map of troop movements against a defensive line on the southeastern tip of a landmass
Map of the Naktong Defensive line, September 1950.
The Pusan Perimeter on September 15. The blue arrow indicated the Battle of Inchon , which had ended the attack on the perimeter
Several rows of deceased bodies lie side by side with bullet wounds to the back
Bodies of Hill 303 massacre victims gathered near Waegwan, South Korea, many with their hands still bound.
A pair of heavily damaged tanks destroyed in a ditch
North Korean T-34 tanks destroyed by US Air Force bombs near Waegwan
North Korean,
Chinese and
Soviet forces

South Korean, U.S.,
Commonwealth
and United Nations
forces