SPAATZ [US Army general]: Did the jet airplane really have a chance to win against us?
GOERING: Yes, I am still convinced, if we only had four to five months more time. Our underground installations were practically all ready. The factory at Karla (?) had a capacity of 1000 to 1200 jet airplanes a month. Now with 5000 to 6000 jets the outcome would have been different.
VANDENBURG [US Army Air Force lieutenant general]: But could you train sufficient jet pilots, considering your shortage in oil?
GOERING: Yes, we would have had underground factories for oil, producing a sufficient quantity for the jets. The transition to
jets was very easy in training. The jet pilot output was always ahead of the jet aircraft production.
SPAATZ: Could Germany have been defeated by air power alone, using England as a base, without invasion?
GOERING: No, because German industry was going underground, and our counter measures could have kept pace with your bombing.
Uh huh. That sounds familiar.
https://cgsc.contentdm.oclc.org/digital/collection/p4013coll8/id/4149