Just to update on this. The Swiss franc has fallen back, but to a level the Swiss National Bank is happy with. It is only if it dives sharply from here on in they will start repatriating money from the USA.

It's unlikely that the Swiss franc will fall given how well run Switzerland is. But yes, in theory, they could cause a global market crash just repatriating stuff for domestic reasons.

No country stays rich forever - all it takes is one bad ruler making mistakes and the strongest states run into problems.