First I would say most definitely that that no nation with any common sense would not send ANY of its troops abroad if there was an imminent threat of hostilities or invasion.
I have little doubt that for whatever reason there are foreign troops here that have ill intent towards the citizens of this country. Hell, we cant even stop nobodies (usually from countries ending in stan) who want to see nothing short than another 9/11.
Simple fact is that tensions are mounting, people are nearing the edge of their ropes, other countries and individuals want to see us fall so they can pick up the pieces, and internally power corrupts... absolutely.
What can we do. Recognize that vigilance is key. As with the original "Minutemen" of the first revolution we must all be ready to move at a moments notice regardless of how the chips fall.