July-September, 1950: Battle of the Pusan Perimeter Summary

  • Last updated on November 11, 2022

North Korean forces invaded South Korea on June 25, 1950, advancing southward quickly despite U.S. military intervention. After defeats at Osan, the Kum River, and Taejon, the U.S. Eighth Army established in late July a defensive position in the southeast corner of the peninsula. A rectangular area, the Pusan Perimeter was about eighty miles from north to south along the Naktong River and fifty miles east to west to just north of Yongdok on the Sea of Japan. Defending it was the U.S. Twenty-fourth and Twenty-fifth Infantry and First Cavalry Divisions together with the First, Third, Sixth, Eighth, and Capital Divisions of the Republic of Korea (ROK), guided by General Walton Walker.

North Korean forces invaded South Korea on June 25, 1950, advancing southward quickly despite U.S. military intervention. After defeats at Osan, the Kum River, and Taejon, the U.S. Eighth Army established in late July a defensive position in the southeast corner of the peninsula. A rectangular area, the Pusan Perimeter was about eighty miles from north to south along the Naktong River and fifty miles east to west to just north of Yongdok on the Sea of Japan. Defending it was the U.S. Twenty-fourth and Twenty-fifth Infantry and First Cavalry Divisions together with the First, Third, Sixth, Eighth, and Capital Divisions of the Republic of Korea (ROK), guided by General Walton Walker.

North Korea’s Third, Fourth, Sixth, Eighteenth, and Twelfth Guards and elements of its Thirteenth and Fifteenth Infantry and 105th Armored Divisions, though exhausted and understrength, initiated fierce fighting for over a month. No longer able to use previously devastating flanking and rear attacks and subject to constant U.S. air and naval bombardment, the North Korean forces, under Choe Yong Gun, battered but did not destroy the Pusan Perimeter.

The South Korean forces successfully defended Taegu, allowing supplies and reinforcements to arrive at Pusan behind shorter logistics lines. The amphibious landing assault at Inchon on September 15, 1950, and then interdiction of North Korea’s extended logistics lines enabled U.S. and South Korean forces to break out of the Pusan Perimeter and move northward swiftly after September 19.

U.S. Marines marching through Pusan on their way to the front. (U.S. Marine Corps)

Categories: History Content