During World War II, LeMay enjoyed a meteoric rise as a combat commander in the Eighth Air Force. His insistence on training and the tight "combat box" formation allowed the B-17s and B-24s to withstand Luftwaffe attacks in their bombing raids over Germany. After a successful tour in England, LeMay was summoned to the Pacific where he devised low-level incendiary bomb tactics for the 20th Bomber Command's B-29s. These tactics gutted Japanese cities and hastened the end of the Second World War.