Kind of funny that the gear used to fight one terrible war overseas is sent back to our own country and used to fight another terrible war domestically, huh?
[1] http://www.businessinsider.com/program-1033-military-equipme...
http://longnow.org/seminars/02010/may/03/deviant-globalizati...
And why, after crime has continued to drop dramatically, has SWAT-ification continued to increase (if not accelerated) rather than plateau or even drop in response?
That said, you do raise a good point that it's career-suicide to advocate reducing police budgets in the US unless absolutely necessary -- and even then it isn't ever well-received.
(Which makes the (in)ability to actually reduce staffing a secondary problem, at best.)
But none of that excuses continued growth in the face of plunging crime, let alone the acceleration in use of such tactics.