(Ireland had some problems just after the crunch but a) entirely because they took on a bank they could have let fail and b) they’ve paid that off now.)
Going back to my original point: if increasing your revenue faster than increasing your interest payments, you can do this forever. Sure, the credit crunch gave some countries a shock, but you really should read up on exactly how egregious the Greek borrowing situation was. It was insanely unsustainable. Germany, Denmark, Sweden, France, Slovenia? They'll be fine.
China has not that problem. The only danger for China is inflation (that can be controlled with, for instance, taxes), otherwise, the People's Bank of China can buy directly the debt and nothing would happen. In fact, they could just stop emitting debt, but that would be inconvenient for banks and other big investors.
Private and local government debts is a different issue.
This? It’s not sustainable. Sooner or later this will result in a correction. This could range from aggressive budgetary measures, an internal crisis all the way to China monetising its overseas investments (which are extremely extensive).