Despite the hopes of the bomber advocates and the fears of many others, the start of World War Two did not see one or two knock-out blows by bomber aircraft pulverising key elements of any combatant nation. No cities were flattened, and even into the May 1940 German advance bombing attacks were crucial only when combined with the threat or use of ground forces.

RAF Bomber Command’s hope that its unleashed bombers would, like a series of rapier thrusts, crucially damage German war capability was quickly found to be a vain one. Worse, even the power turret-protected Vickers Wellingtons were found unable to defend themselves effectively in daylight, and Bomber Command switched thereafter to night attacks.