It's actually fiat money that makes it possible to escalate conflicts to such a disastrous level in the first place.

If you're on a gold standard and your war chest starts to run out, you must either find a wealthy lender (hard), press the plunder of your citizenry (limited & bad for morale) or start thinking about a peace deal.

With fiat you can just fire up the printing presses, the later consequences be damned (should you even be aware of them). The first one to have their economy collapse loses, but in the meantime the slaughter can go on.