During the campaign, conventional weapons such as explosives, incendiary bombs, and napalm destroyed nearly all of the country's cities and towns, including an estimated 85% of its buildings.

For the entire duration of the war, areas on the border between Korea and China were excluded from bombing because of U.S. State Department concerns.

[5] Between June and October 1950, USAF Far East Air Force (FEAF) B-29 bombers carried out massive aerial attacks on transport centers and industrial hubs in North Korea.

"[10] Fraught with a rapidly evolving frontline, conflicting information, and green troops as UN forces retreated, FEAF's rearguard actions in July would also see the bombing of South Korean targets in Seoul and Andong, resulting in significant civilian deaths such as those at Yongsan.

"[10] In October 1950, Stratemeyer requested permission to attack Sinuiju, a provincial capital with an estimated population of 60,000, "over the widest area of the city, without warning, by burning and high explosive."

MacArthur's headquarters responded the following day: "The general policy enunciated from Washington negates such an attack unless the military situation clearly requires it.

"[10] Following the intervention of the Chinese in November, MacArthur ordered increased bombing on North Korea, which included firebombing against the country's arsenals and communications centers and especially against the "Korean end" of all the bridges across the Yalu River.

[12] On 3 November Stratemeyer forwarded to MacArthur the request of Fifth Air Force commander General Earle E. Partridge for clearance to "burn Sinuiju."

Stratemeyer sent orders to the Fifth Air Force and Bomber Command to "destroy every means of communications and every installation, factory, city, and village".

In the wake of the Kanggye attack, FEAF began an intensive firebombing campaign that quickly incinerated multiple Korean cities.

[19] At the conclusion of the war, the Air Force assessed the destruction of 22 major cities as follows:[20] The bombing campaign destroyed almost every substantial building in North Korea.

[24][25] Dean Rusk, the U.S. State Department official who headed East Asian affairs, concluded that America had bombed "everything that moved in North Korea, every brick standing on top of another.

[3] In November 1950, the North Korean leadership instructed the population to build dugouts and mud huts and to dig tunnels, in order to solve the acute housing problem.

[27] In an interview with U.S. Air Force historians in 1988, USAF General Curtis LeMay, who was also head of the U.S. Strategic Air Command, commented on efforts to win the war as a whole, including the strategic bombing campaign, saying “Right at the start of the war, unofficially, I slipped a message in "under the carpet" in the Pentagon that we ought to turn SAC lose with some incendiaries on some North Korean towns.

"[19] British Prime Minister Winston Churchill privately criticized the American use of napalm, writing that it was "very cruel", as U.S. forces were "splashing it all over the civilian population", "tortur[ing] great masses of people".

"[17] Public statements by the UN Command obfuscated the extent of the destruction of North Korean communities with euphemisms, for example by listing the destruction of thousands of individual "buildings" rather than towns or villages as such, or reporting attacks on North Korean supply centers located in a city with language suggesting that the entire city constituted a "supply center".

On 13 May 1953, 20 F-84s of the 58th Fighter Bomber Wing attacked the Toksan Dam, producing a flood that destroyed 700 buildings in Pyongyang and thousands of acres of rice.

[36][37] The bombing of these five dams and ensuing floods threatened several million North Koreans with starvation; according to Charles K. Armstrong, "only emergency assistance from China, the USSR, and other socialist countries prevented widespread famine.

[39] In a 1988 interview Curtis LeMay stated that about 20% of the North Korea's population had died during the war, including the UN air campaign, stating that “Over a period of three years or so we killed off, what, 20 percent of the population of Korea, as direct casualties of war or from starvation and exposure?”[28][26][29] Armstrong states that the bombing had a profound, long-lasting impact on North Korea's subsequent development and the attitudes of the North Korean people, which "cannot be overestimated": Russian accusations of indiscriminate attacks on civilian targets did not register with the Americans at all.

But for the North Koreans, living in fear of B-29 attacks for nearly three years, including the possibility of atomic bombs, the American air war left a deep and lasting impression.