Iraq, Afganistan, S. Korea, Germany, Japan...
How many combat divisions are still stationed in CONUS? How many NG units are not already deployed overseas and are available and able to respond? Ever wonder why Zero has not brought the troops home as promised during the campaign?
As luck will have it, things may be developing too quickly for President Zero's proposed National Thug Corps to be organized against the people and, as another poster pointed out, even Japan at the height of her power hesitated to send troops ashore here. I think UN "Peace keepers" would be equally reticent.
Personally, I know what I would do if I saw blue helmets in my town.
There are plenty of troops here, they are called ‘civilians with guns.’ Nothing, not even orders from any president, would prevent US troops from picking up stakes and getting back to the US, even if they had to do it through Mexico.