That is one outcome, assuming China tries to repay their debts. And as you are aware that hasn't worked out very well for Japan. If I was China and shit hits the fan, I would declare bankruptcy. It would hurt everyone but a shock like that probably has less chance of triggering a revolution than 20 years of decline.
In the case of both Japan and China, most of their debt is held internally.
That's why Japan is debasing the Yen, instead of performing a traditional default. They're unable to afford their debt, but if they just outright default, that will hammer their economy in one big hit - the creditors are the Japanese people. The Yen debasement hits them as well, and reduces the real value of the debt, but the premise is it's a gradual process they can adjust to over time (and the politicians get to lie about what's happening, another reason they all universally prefer inflationary schemes).
