Allies Break Out: Pusan Perimeter Crumbles in Korean War

U.S. Eighth Army and United Nations forces smashed through North Korean lines and broke out of the Pusan Perimeter, linking up with MacArthur's Inchon landing force to trap the overextended enemy. The coordinated offensive reversed the war's momentum within days, liberating Seoul and pushing the shattered North Korean army back across the 38th parallel. The breakout began on September 16, 1950, one day after MacArthur's audacious amphibious landing at Inchon, 150 miles behind enemy lines. The Eighth Army, commanded by General Walton Walker, had been holding the Pusan Perimeter for six weeks against continuous North Korean attacks. The perimeter, roughly 140 miles long and 80 miles deep, represented the last foothold of the UN forces on the Korean peninsula. Walker's breakout was timed to coincide with the Inchon landing, creating a pincer movement that would cut North Korean supply lines and trap their forces between two advancing armies. The North Korean army, which had committed nearly all its combat power to the assault on the perimeter, suddenly found itself cut off from its logistics base. The retreat became a rout as North Korean units, running out of ammunition and fuel, broke apart under combined ground and air attack. Within two weeks, UN forces had recaptured Seoul and crossed the 38th parallel into North Korea, pursuing what appeared to be total victory. The rapid reversal from desperate defense to triumphant advance was one of the most dramatic in modern military history, though the subsequent Chinese intervention in November would transform the war yet again.