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.
