The objectives and use of air power were in large measure determined by the movement of the ground war, once the brief strategic bombing campaign was closed out. The momentum of the initial North Korean invasion carried its forces forward, pushing the retreating Americans and the remnants of the Koreans into the Pusan area. There, behind a defensive perimeter, the Eighth Army dug in and held.
That stubborn defense, coupled with a massive air offensive flown by Mustang fighter-bombers from Japan staging thorough Taegu, bought time. The RoK army regained some strength, reinforcements arrived for the Eighth, and the NKA drive was halted and turned. MacArthur's landing at Inchon followed, under an umbrella of complete air superiority and preceded by B-29 interdiction strikes, Navy fighter sweeps, USAF and Navy ground attacks to support the invasion, and Marine Corps close support.
On 17 September the Eighth began its drive northward, gathering momentum as it moved. B-29s flew ahead, destroying bridges on the route of the retreating NKA, and blasting their troops in a carpet bombing attack running 1 mile (1.6 km) along the Naktong river. Seoul was recaptured, and by 1 October the RoK army was crossing the 38th parallel, moving as fast forward as it had earlier retreated.
By then, the Chinese were committed to fight, and had moved ground and air units into the area just north of the Yalu river. On 26 November, they launched a major offensive and drove the UN forces back down the peninsula to a line of resistance south of Seoul, where the war began its long stalemate. The UN forces countered in early 1951, and moved forward to a line roughly equivalent to the 38th parallel. Truce talks began on 10 July 1951, and the armistice was signed on 27 July 1953.
To describe a war like the Korean conflict in limited space allows no room for endless narratives of hammering machine guns and exploding MiGs, as pertinent as they are. Instead, consider the air war as three different, although related and simultaneous operations: the strategic bombing campaign, which was a shortlived attack against short-listed targets; the interdiction campaign, which isolated the battlefield, cut supply and communication lines, and supported the advance or covered the retreat of the UN ground armies; and the air-superiority campaign, that pitted Sabres against MiGs in an aerial gunfight.