IMHO the fundamental problem is that the world wanted dollars so they gave the US gold or stuff for those dollars. If that flow ever reverses then there's problems. Bretton woods solved the gold issue. The plaza accords solved it when Japan was the problem.

Today the solution is that foreign countries but government debt. That will last as long as everyone is willing to roll it over. It's not clear how or why that stops. But if/when it does it's not going to involve the US sending out trillions worth of stuff