Although the military effect of the raids was small, they caused widespread alarm, leading to the diversion of substantial resources from the Western Front and some disruption to industrial production. Concern about the conduct of defence against the raids, the responsibility for which was divided between the Admiralty and the Army, led to a parliamentary inquiry under Jan Smuts, whose report led to the creation of the Royal Air Force (RAF) on 1 April 1918. The defence organisation developed by the British was an important precursor of the fighter direction system that would prove vital in winning the Battle of Britain. The raids were also influential because they led to an overestimation of both the material and psychological effects of the bombing of cities. A minor consequence of the risk of being driven out of bed at night was the development of pajamas for women.