I highly doubt troops would be used. It would be the end of the USA. Trade with Nations would cease. A world boycott would happen.
And btw it would, to actually bring it off, require a war declaration in Congress and use of the draft. You think that will happen?
It's not like Afghanistan or Iraq where the point was to destroy the infrastructure. Then rebuild it. In this case they HAVE TO KEEP IT INTACT. Or the whole point of the operation is a failure. People forget we SHARE the largest Undefended border. If 1% of Canada decides to go full guerrilla that's 400,000 potential terrorists who can strike back unless they cover the entire 49th parallel and all the water in between. The means to do that doesn't exist. The massive buildup to do it, train troops, and then hold it, as well as the cost?
Think about it.