British historian Richard Overy revisits the case for the World War II Allied air offensive in 'The Bombers and the Bombed'

Books about the World War II Allied aerial bombing offensive against the Axis inevitably center on two questions: its strategic efficacy and its morality.

Richard Overy’s penetrating new study, “The Bombers and the Bombed: Allied Air War Over Europe, 1940-1945” (Viking, 592 pp., $36), focuses more on the former than the latter, although those inclined to debate ethics will find plenty here to inform their judgments.

Overy, a British historian and World War II specialist, has authored numerous books on that conflict. Twenty years ago, in “Why the Allies Won,” he argued there was “something fundamentally implausible about the contention of bombing’s critics” that bombing was ineffective or counterproductive.

How could dropping millions of tons of explosives on factories and cities not seriously weaken the enemy? He concluded then that “the air offensive was one of the decisive elements in Allied victory.”...