https://www.investopedia.com/articles/investing/080615/china...
Second, China needs that debt to be able to manage it's own currency. And though the Fed is not supposed play games like international currency war ... it will. The Fed and the USD are well poised to soak up any problems that China tries to play with USD.
It's also a game of confidence: do USD holders worldwide think that China can sink the USD with a little bit of war? Or is the global petrodollar resilient? Given the numbers and ratios ... it's clear that China probably won't win, cred remains in the USD etc.. So - it would have to be a coordinated shock - if there were both economic problems in the US, and dollar problems, and shocks in some other way and then China started playing games ... well that's something else.