a) You haven't been paying attention to potential adversaries and your equipment and people are in the wrong location at the wrong time.
b) Your trying to do global projection without pre-positioning as a part of your capability mix. 15/
a) a light weight material breakthrough?
b) lasers, plasma, rail guns, hypersonics?
While we're waiting for the magic to happen there is an opportunity now to build a game changing next gen MBT. 16/