As long as the USAF is stuck in "pick one" budgets, I understand why. But a fight with China will see tankers blown out of the sky in a big hurry.
It seems that NGAS is another one of Frank Kendall's failed trial balloons. Remember when he proposed a B-21 unmanned companion, then reversing course year later? We can't afford NGAD at $300 million a pop, but we are going to develop a stealthy tanker that is bigger than NGAD but smaller than KC-46.
It was dumb on two accounts. The "oldest, smallest, and least ready" Air Force is in the middle of recapitalizing almost everything - trainers, tankers, AWACS, fighter, the F-22, ICBMs, etc. It was also going to add a very expensive stealth tanker which would also be technically very challenging? How do you ensure the boom is low observable? And what about the CONOPS? Would there be enough fuel to offload which would be tactically meaningful? Last, how was all this going to be paid for?
It would seem that it would be much more cost efficient to build range into NGAD and the F-35 through an adaptive engine than spend billions on a stealth tanker. Improve active and passive air defenses at bases in the region and stockpile munitions and fuel to support a stand in force. With adequate air defenses and CCA escorts for HVAs, tankers should be able to top off US fighters from sanctuaries in the Western Pacific before entering contested airspace.
Once NGAD and CCAs are fielded, the AF can revisit a low observable tanker platform. Perhaps it will be unmanned and similar in size to a MQ-25?