I'm trying not to get my hopes up that it's IA but even if they said it was a training exercise, what better cover story is there than that to mask moving things into place?

The only question is how common is this sort of thing - did it happen leading up to other inauguration days? Did it happen leading up to the Iraq war (in the US or overseas bases)? If the latter then I'd be more inclined to believe it's IA and the military has decided we are officially at war with insurrectionists.