I see your point, but to suggest the US would bomb Europe, China or Russia for abandoning the dollar (Should it become unpredictable, like a currency crisis) is extremely unlikely. Having fiat as a reserve currency always posed this problem. In my eyes, is the remedy a gold or bitcoin standard?
The current model is finite
Saddam Hussein began trading for oil without dollars. Ghaddafi was launching a gold-backed Dinar currency. What happened to their countries? Maybe it won't be a hot war from the start. Could be a cyber attack or biological warfare. Anyone who challenges USD supremacy gets met with force, period. It never has been and never will be otherwise.
A bitcoin standard is one potential remedy. But no standards are needed really, just let everyone become their own financial sovereign.