>>18076477 (OP)
It lengthened WW2 because it prevented collapse of military industrial complex but it also had no military effect. America never bombed a power plant. It never bombed tank factories and the aircraft factories it bombed were easy to disperse and the best Nazi aircraft were made in France.
The concept of strategic bombing means nothing because the vast majority of manufacturing is extremely small scale and bombing the major projects the enemy is wasting time on isn't worthwhile. The b17s were incapable of hitting trains and also synfuel was a scam. What it bombed had no value.
Tactical level bombing of ground forces was done sometimes and had some effect but the strategic campaign mostly killed civilians (not that they cared, they died of meth anyway) and was just a excuse to dump bombs.
The main impact of the air campaign was for American airpower to be btfo against the interceptors, air defense and flak. Even though the losses from flak were low the flak damaged a large amount of aircraft and the bombing was costly up to end of the war.
>>18076486