Could you provide more information on what you mean by "repudiated the debt"? Does this mean reneging on US Treasury bonds? Because that's nuclear. That causes fixed income markets to implode and brings upon GFC 2.0.
The risk of losing their profit is what I meant by repudiating the debt.
Chinese investor interests hold ~ $800b of debt. Thats not the state, but it is doubtful the state would bail them out: They pick and chose how to fix problems like this and I think the message "You invested in America not us, you wear the risk" would be beneficial to them.