Incendiary device UN pilots used 70,000 gallons of napalm, with approximately 60,000 gallons of this thrown by US forces. Winston Churchill, among others, criticized American use of napalm in Korea, calling it "very cruel", as the US/UN forces, he said, were "splashing it all over the civilian population", "tortur[ing] great masses of people". The American official who took this statement declined to publicize it. During the Vietnam War, the U.S. Air Force developed the CBU-55, a cluster bomb incendiary fuelled by propane, a weapon that was used only once in warfare. Napalm however, became an intrinsic element of U.S. military action during
Incendiary ammunition night fighters for use against military zeppelins threatening the British Isles. The flammable hydrogen gas of the zeppelins made incendiary bullets much more deadly than standard ones which would pass through the outer skin without igniting the gas. Similarly, incendiary ammunition was used against non-rigid observation balloons. The British Royal Flying Corps forbade the use of incendiary ammunition for air-to-air combat with another airplane, as their use against personnel was at first considered to be a violation of the St. Petersburg Declaration. Pilots were permitted to deploy them against only zeppelins and balloons, and they were additionally restricted to shooting