Krugman has this to say about it:
For those not familiar with how financial markets work, US Treasuries are the ultimate safe asset, used as collateral for everything. Even a hint that some Treasuries might not be honored could bring everything to a screeching halt
Musk and Trump are both in the habit of stiffing people they owe money. If markets even suspect that this habit will extend to Treasuries, God help us
Only usa can have total control no other currencies could ever replace it because they are not as good at being world leaders? Or something like that? All wealth would just move, probably half china half eu, and even then, it may already have happened mostly because this isn’t news to anyone with a brain