 The war in Europe had cast grave doubt on the Air Corps ' doctrine that fighters could not shoot down bombers and the bomber will always get through . In the Battle of Britain the British Royal Air Force had demonstrated that it could shoot down bombers , while its own bomber force had suffered such heavy losses over Germany that it had abandoned daylight bombing in favor of night raids . Nonetheless , the planners held firm in their belief that , since American bombers were better armed and armored than their British or German counterparts , the bombers would get through , even in daylight , and that enemy fighter strength could be destroyed on the ground by bombing airbases and factories . " Each of us , " Kuter wrote years later , " scoffed at the idea that fighters would be needed to protect bombers , to enable bombers to reach their objective . In preparing AWPD @-@ l , we stayed in that rut . " Walker was promoted to colonel on 1 February 1942 . 
