If I was the Chinese et al I honestly wouldn't write the cheque. At what point does national debt drown an economy? Does crippling debt not normally precipitate war with the debtees? I'm a little worried.
The Chinese would never do something so rash... they know they have to keep loaning us money, because it's either that or have their debt become worthless. They would also never go to war with us, outside of a battle over Taiwan that has become increasingly unlikely. What's the point? No one wins with war.
And yeah, crippling debt is normally a bad thing, but you have to remember that we are making up economics we go along. As long as economists keep saying that crippling debt is ok, everything functions. As soon as the theory changes, then we're all screwed.