Battle of Pusan Perimeter

Battle of Pusan Perimeter
Part of the Korean War
Men sit in foxholes watching over a lower terrain feature
Troops of the U.S. 27th Infantry await North Korean attacks across the Naktong River from positions on the Pusan Perimeter, September 4, 1950.
DateAugust 4 – September 18, 1950
LocationPusan, South Korea
ResultUnited Nations victory

 United Nations

 North Korea
Commanders and leaders
United States Douglas MacArthur
United States Walton Walker
South Korea Chung Il-Kwon
South Korea Shin Sung-Mo
United States George Stratemeyer
United States Arthur Dewey Struble
North Korea Choi Yong-kun
North Korea Kim Chaek
North Korea Kim Ung
North Korea Kim Mu Chong
Units involved
United States Eighth Army
United States Fifth Air Force
United States Seventh Fleet
South Korea ROK Army
South Korea ROK Navy
(Main article)

North Korea People's Army
North Korea People's Navy
North Korea People's Air Force

(Main article)
141,808 total (92,000 combat)[1]98,000 (70,000 combat)[2]
Casualties and losses
South Korea: 40,000?+[3]
United States:
4,599 killed
12,058 wounded
2,701 missing
401 captured[4]
60 tanks
United Kingdom: 5 killed, 17 wounded
India: 1 killed
2 war correspondents
60,504 total casualties
63,590 total casualties
3,380 captured[5]
239 T-34 tanks
74 SU-76 guns

The Battle of Pusan Perimeter was a large-scale battle between United Nations and North Korean forces lasting from August 4 to September 18, 1950. It was one of the first major engagements of the Korean War. An army of 140,000 UN troops, having been pushed to the brink of defeat, were rallied to make a final stand against the invading North Korean army, 98,000 men strong.

UN forces, having been repeatedly defeated by the advancing North Koreans, were forced back to the "Pusan Perimeter", a 140-mile (230 km) defensive line around an area on the southeastern tip of the Korean Peninsula that included the port of Pusan. The UN troops, consisting mostly of forces from the Republic of Korea (ROK), United States and United Kingdom mounted a last stand around the perimeter, fighting off repeated North Korean attacks for six weeks as they were engaged around the cities of Taegu, Masan, and P'ohang, and the Naktong River. The massive North Korean assaults were unsuccessful in forcing the United Nations troops back further from the perimeter, despite two major pushes in August and September.

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. However, the UN used the port to amass an overwhelming advantage in troops, equipment, and logistics, and its navy and air forces remained unchallenged by the North Koreans during the fight. After six weeks, the North Korean force collapsed and retreated in defeat after the UN force launched a counterattack at Inchon on September 15. The battle would be the furthest the North Korean troops would advance in the war, as subsequent fighting ground the war into a stalemate.


A map showing successive North Korean advance. The Pusan Perimeter is the border of the green portion of the peninsula.

Outbreak of war

Following the outbreak of the Korean War, the United Nations decided to commit troops in support of the Republic of Korea (South Korea), which had been invaded by the neighboring Democratic People's Republic of Korea (North Korea). The United States subsequently sent ground forces to the Korean peninsula with the goal of fighting back the North Korean invasion and to prevent South Korea from collapsing. However, US forces in the Far East had been steadily decreasing since the end of World War II, five years earlier, and at the time the closest forces were the 24th Infantry Division of the Eighth United States Army, which was headquartered in Japan. The division was understrength, and most of its equipment was antiquated due to reductions in military spending. Regardless, the 24th Infantry Division was ordered into South Korea.[6]

The Korean People's Army (KPA), 89,000 men strong, had advanced into South Korea in six columns, catching the Republic of Korea Army (ROKA) by surprise and completely routing it. The smaller ROKA suffered from widespread lack of organization and equipment, and was unprepared for war.[7] Numerically superior, KPA forces destroyed isolated resistance from the 38,000 ROKA soldiers on the front before moving steadily south.[8] Most of South Korea's forces retreated in the face of the advance. By June 28, the KPA had captured South Korea's capital of Seoul, forcing the government and its shattered forces to retreat further south.[9] Though it was steadily pushed back, South Korean forces increased their resistance further south, hoping to delay KPA units as much as possible. North and South Korean units sparred for control of several cities, inflicting heavy casualties on one another. The ROKA defended Yongdok fiercely before being forced back, and managed to repel North Korean forces in the Battle of Andong.[10]

Outnumbered and under-equipped US forces—committed in piecemeal fashion as rapidly as they could be deployed—were repeatedly defeated and pushed south. The 24th Division, the first US division committed, took heavy losses in the Battle of Taejon in mid-July, which they were driven from after heavy fighting. 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 Pusan area.[11][12] Soon after, Chinju to the west was taken, pushing back the 19th Infantry Regiment and leaving open routes to Pusan.[13] US units were subsequently able to defeat and push back the KPA on the flank in the Battle of the Notch on August 2. Suffering mounting losses, the KPA force on the west flank withdrew for several days to re-equip and receive reinforcements. This granted both sides several days of reprieve to prepare for the attack on the Pusan Perimeter.[14][15]