Air Force bites off more than it can chew.

Or fund.  The big three money suckers.  The F35 fighter.  Cost is outta sight.  The software isn't finished.  The gun doesn't fire, the engines cannot take more than 5.6 G.  The KC-46 tanker project.   The Air Force managed to gold plate a simple "put tanks inside a well proven airliner" project into an ongoing boondoggle that is running late and over budget.  The new B-21 strategic bomber, this is going to be a somewhat smaller, and hopefully cheaper, version of the B2 bomber.  It's just getting started, but the project did make it thru a bid challenge by the loser[s]  (Boeing and Lockheed).  Aviation Week did not offer much in the way of cost estimates on the big three.  I'd guess $1 trillion over the next 10 years. 

And, after the top three projects, we have a four projects  in to the Request for Proposal, going out for bids, study project phase.  We have a new jet trainer to replace the capable but ageing T-38 Talon. A new ICBM to replace the Minuteman III.  The Long Range Standoff Missile to arm the new B21, and re arm the B-52, B1, B2 fleet.  A new helicopter for VIP transport. 

And even further out, an A10 replacement.  Which is hard to think about.  The existing A-10 is good at what it does.  It's a ground attack fighter that can fly low enough and slow enough for the pilot to see and hit his ground target.  Once the airplane can do that, it isn't fast enough to dogfight with mach 2 jet fighters.  The answer to this short coming is to provide fighter cover for the A-10s as needed.  Bombers have needed fighter escort ever since WWII.  

   The Air Force isn't going to be able to round up the funding to do all of this stuff at once.