The rest of the world holds enough of the US debt that no one would have to fire a shot for parts of the world to retaliate. Looking at the rise in Tbill yields, it may have already started on some level.
That sword cuts both ways. I think we're betting that the other side is less willing to tolerate global impoverishment than the others, and to what degree. I hope we don't push it to the degree that China decides to call our bet.