Well, in all fairness, you can have a well-run fiat currency. You can even have deflation with a fiat currency. It just never seems to happen, does it?
As for the petrodollar wars, the paradox is that the wars are there to force up demand for the FRN, thus saving it and buoying up its value. But the FRN must be destroyed to pay for all of the wars. So, it's salvation is also its destruction.
And how many people are dying for this fools' errand?!