The Battle of the Pusan Perimeter, known in Korean as the Battle of the Naktong River Defense Line, was a large-scale battle between United Nations Command (UN) 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 south to the brink of defeat, were rallied to make a final stand against the invading Korean People's Army (KPA), 98,000 men strong.