Prewar hopes that bombers could shorten wars by striking factories, railways, and morale behind lines.

B-17 daylight doctrine, heavy guns, and precision bombing aimed at industrial targets, tested in combat.

Britain shifts to night area bombing with the Lancaster, emphasizing payloads and area destruction.

B-29s adopt incendiaries for low-altitude firestorms in Japan, reshaping urban devastation and tactics.

Debates over civilian casualties, Dresden, morale, and the line between military aim and humanitarian cost.