In December 1940, after the most dramatic phase of the Battle of Britain had ended, Maurice Hankey wanted to discover just how much damage German bombing had done to British production. The long-time secretary to the Committee for Imperial Defence, Hankey had joined the War Cabinet when World War II commenced. In this role he had argued strongly, and increasingly unsuccessfully, in favor of a strategic bombing policy aimed at destroying Nazi Germany's access to oil. He also regularly argued against any bombing aimed at the destruction of German morale, viewing it as fruitless and counterproductive.

Not surprisingly, Hankey was eager to find out the precise damage that the Luftwaffe had inflicted on British industry. He asked the Ministry of Home Security to send him data on individual bomb hits on different sectors of the British economy. On December 11, the ministry replied. During the three most intense months of the Battle of Britain, when the United Kingdom was supposedly fighting for its very survival against the all-powerful and victorious Luftwaffe, exactly seventeen German bombs had caused “severe” damage (the highest damage rating) to Britain's aircraft and aero-engine production, electricity services, gas supplies, water industry, oil infrastructure and all food service industries –combined. Even more remarkably, the highest priority target of Luftwaffe bombers during the battle, Britain's docks and harbors, had not been hit by a single bomb that did “severe” damage.