The bombing operations forced Germany not only to use its planes defensively instead of tactically against the Soviet Union (and build high altitude fighters to

The bombing operations forced Germany not only to use its planes defensively instead of tactically against the Soviet Union (and build high altitude fighters to begin with), but also forced them to spend an enormous amount of resources on anti-air guns, bunkers for civilians, military assets and manufacturing, radar systems, and what not, all of which could have being spend. As especially the USA's industrial output was much larger than Germany's, bombers might still have been a good investment, even if it didn't actually reduce Germany's industrial capacity, because it did reduce its capacity to wage ground war. EDIT: Also, even if Germany's industrial output did grow during WWII, it still tied up an enormous amount of resources: "The Allied bombing campaign also tied up valuable manpower, with Albert Speer (Germany's Minister of Armaments) estimating that in the summer of 1944 between 200,000 and 300,000 men were permanently employed in repairing oil installations and placing oil production underground. " https://en.wikipedia.org/wiki/Economy_of_Nazi_Germany#Wartime_production https://en.wikipedia.org/wiki/Economy_of_Nazi_Germany#Wartim...