I guess the USD has always been considered a "safe haven" for...

I guess the USD has always been considered a "safe haven" for investors - so whenever there's a war, a crisis, a disaster, the USD generally rallied and that's been a reflex reaction for investors.

Also, we know the financial system is a deck of cards. And the foundation is the US system and its currency. So basically, if their currency fails, everyone else is pretty much stuffed. They are the reserve currency.