The Failure of Bomber Command, 1939-1941
Since at least some of Bomber Command's limitations were generally understood, the British government welcomed President Franklin D. Roosevelt's request on September 1, 1939, that the belligerents refrain from an unrestricted air war that would endanger civilians. This was interpreted as excluding almost any attacks on industrial targets located in or near cities. The Nazis also professed to welcome Roosevelt's appeal. The French favored "restraint" even if the Germans launched a major offensive in the West, lest their poorly defended industry suffer devastation by the Luftwaffe, but the British disagreed.
The British limited their air effort against Germany to attacks on the German navy and to dropping propaganda leaflets on German cities. The Allies would have been well advised to invade the Rhineland while the German forces were tied down in Poland, but the opportunity slipped by without even being noticed at the time--it was beyond the mental horizon of the slow-thinking Allied leaders. Their grand strategy was to build up their forces gradually and launch a major land offensive only in the later stages of a war, after blockade and bombing had weakened Germany. Whatever the defects of the general strategy, the British decision to hold back in the air was reasonable. The British continued to follow this policy after indiscriminate German bombing in Poland released them from the pledge of mutual restraint. Ludlow-Hewitt expected a long war; he planned a gradual expansion of Bomber Command and held back men from front-line squadrons to increase the strength of training units. 1
That the decision to hold off on bombing was prudent was soon shown when even limited attacks on the German fleet ended disastrously. On September 4, the day after Britain declared war, fourteen Wellingtons and fifteen Blenheims set out to attack the German fleet near Wilhelmshaven. The formations became disorganized in clouds; ten planes turned back, and the rest made ragged attacks. While the Wellingtons bombed from high up, the Blenheims, going in low, damaged a cruiser slightly (one Blenheim crashed into it) and hit a pocket battleship