At which point your currency/bonds are worthless to everyone who doesn't have to pay taxes with them since you look for reasons to break your promises when things don't go your way.
I doubt it. Maybe we will be downgraded from AAA to AA, but I doubt we would see more than that. In contrast, China would lose $600-800 billion and anyone else who wants to use debt as a weapon would think twice.
Anyway, it's never going to happen. America's not going to start WWIII over Taiwan, talk about lose-lose.