How may other countries react if he starts ripping up trade deals? or other agreements?
Future deals will be hard to make, as the world won't be able to trust us. Our 'word' is only good until our next election. That seems problematic.
ISIS may find itself a new target; anything with the name TRUMP on it. Not hard to imagine this.
If he starts dealing with China as a bully, which seems to be the way he operates, I can see them refusing to ship stuff here. Same with Mexico and Canada.
We may be their biggest customers, but we're not their only customer. Our stores would have empty shelves.
They would survive. Would we?