Air warfare of World War II 1920s summarised the faith that airmen during and after World War I developed in the efficacy of strategic bombing. Many said it alone could win wars, as "the bomber will always get through". The Americans were confident that the Boeing B-17 Flying Fortress bomber could reach targets, protected by its own weapons, and bomb, using the Norden bombsight, with "pickle barrel" accuracy. Japanese aviation pioneers felt that they had developed the finest naval aviators in the world. The Luftwaffe was the German Air Force. The pride of Nazi Germany under its leader Hermann Göring, it learned new combat techniques in
Boeing B-17 Flying Fortress British heavy bombers, the Avro Lancaster and Handley Page Halifax, dropped 608,612 long tons (681,645 short tons) and 224,207 long tons (251,112 short tons) respectively. The RAF entered World War II with no heavy bomber of its own in service; the biggest available were long-range medium bombers such as the Vickers Wellington, which could carry up to of bombs. While the Short Stirling and Handley Page Halifax became its primary bombers by 1941, in early 1940, the RAF entered into an agreement with the U.S. Army Air Corps to acquire 20 B-17Cs, which were given the service name Fortress I.