NATO will be fine. They'll just have to up their game a bit militarily. If America wants to be insular and wrap a flag of isolationism around them, it'll hurt in the short term, but after four years of being more independent of Americas tit, its more than likely the US that will find itself less relevant globally.

Even before this, there was already rumblings, not just in China, but elsewhere, about ditching the american dollar standard and returning to the gold standard. That's just going to gain momentum as soon as Trump starts trying to wave his mushroom around.