If they have a bigger bag than their adversary, maybe wars would be shorter since the adversary has to surrender earlier since they can't sustain the expenses.

I see bitcoin as putting a upper limit on how much resources you can spend on war. Similar to the point made by Hivemind Ventures regarding AI and bitcoin.

bitcoin

Orange-pill memes: Would there be less wars on a Bitcoin Standard?

Doubt it. Humans will war over any resource. All anyone needs to do to fund wars is accumulate a bigger bag than their adversary. Bitcoin just makes the funding source obsolete. It does not stop the funding. As Fallout says. War? War never changes.