It has to do with countries not buying US treasuries. That used to be how the dollar system worked. Now that countries aren’t, tariffs are being used as an alternative. You can read the war finance article series for some background: https://advisoranalyst.com/wp-content/uploads/2022/08/zoltan...
There is no issue with countries buying us treasuries. They sail off shelves. Until the current administration started to make it look like there’s a possibility that the country may bankrupt itself, which threw a risk component into US debt for like the first time ever
I think the real risk isn't USA going bankrupt as much as the dollar losing significant value relative to other currencies, thereby making holding US debt a bad deal for overseas holders, and/or possibility that Trump could do something previously unthinkable such as stopping interest payments on debt or trying to "make a deal" and renegotiate payments in some way.
