O’Brien is at his absolute best describing the subtle factors that whittled away Axis combat power. Air and sea power created a situation where the Axis war machine simply could not function anywhere near as efficiently as it needed to.
For example, after the Allied air bombings started, Germany built vast underground aircraft factories to protect production. But that move carried a host of negative side effects. To name a few:
- The direct cost of building new factories in inconvenient places was very manpower intensive.
- The old factories had been sited convenient to resource bases. The new factories were necessarily not near resource bases—they were in areas where one could dig out big new facilities.
-Railroads, by far the most efficient means of transportation, were set up to efficiently move goods to and from the old factories, not the new ones.
Those factories had to be optimized for things like size and compactness, not efficiency and quality control. Aircraft frequently broke down on their way to the front lines. Once damaged, they could not be fixed on the front lines and were effectively useless.
- These effects ultimately mean fewer airplanes produced as the war went on, and dramatic increases in non-operational losses. Citing the German field marshal in charge of aircraft production, O’Brien assessed that the Germans lost approximately half of their planned fighter production in this way. This comports with post-war American assessments, which assessed total German aircraft losses at the front as 15,327 in 1944, and non-operational losses at approximately 15,000. For comparison: total German aircraft losses at Kursk were approximately 159(!)
[there's a graph showing non-operational losses of aircraft]
Data from HtWWW, recreated to improve image quality
The inefficiencies stemming from bombing ruined several would-be German technological panaceas. Germany developed the world’s first operational jet fighter, the Me-262. Lack of fuel meant there was not enough training for its pilots, and maintenance shortfalls meant that about half of the 1,400 Me-262s produced by Germany were lost outside of combat. The Germans developed a dangerous, relatively modern submarine, the Type XXI. They intended to deploy dozens in a way that the Allies would have been hard pressed to fight, but production delays meant that only one ever actually went on a mission.
Allied Bombings Provoked Vastly Expensive Reactions
O’Brien thoroughly documents how expensive Germany’s reaction to Allied bombings was. First, expenditures on anti-aircraft weaponry and fighter planes skyrocketed. The Germans practically denuded the Eastern Front of fighter planes to have more to throw at the bombers. By late 1944, a bare 15% of German aircraft were fighting on the Eastern Front. In the second half of 1943, significantly more concrete was devoted to the construction of protected aircraft factories in Germany than to the entire Eastern Front. The amount of concrete devoted just to protecting Hitler personally from air attack was almost a third of the entire total for fortifications on the Eastern Front
) had drilled small holes in their fuel tanks 
