It need not be a single country. Organizations like BRICS could float it's own currency, and with significant size of the economy of the members, it could pull it off. This is why Trump has been explicitly warning against that.
BRICS might have the wealth. Would you trust that it's going to be legally stable? I wouldn't.
But, in fairness, for the first time in my life I don't trust the US in that way either. I'm beginning to see it as possible that someday the president could make some arbitrary decision that takes everything I have. (Either this president or another - but it's this president who's making the precedents that make it possible.)
