Actually USA is less than one percent of the worlds pop. So the Donald may end up with a near useless dollar which is propped up artificially. Wall street going under is a good thing cause they moved 56,800 factories to China since 2006 right under the Republicans nose. Nice going George.
Now as to world upsets and nukes going poof look no further than Iran. Ignored UN inspection supporting Isis, buying Russian pop guns like crazy. Continues to preach the total destruction of Israel. Canada says they are the single greatest threat to global peace ejecting all diplomates from Syria and Iran while closing embassies. No big deal to the middle east really they've been at it for 4,000 years.
So the seers say a weapon will go off in it's own country. Gas or nuke ? Your guess