Sure, there will still war financing in Bitcoin. But there will be so many more productive alternatives that fighting in a war would be an incredibly bad idea and would result in losing money in the end.

So for example with Israel and Palestine. What would happen is that there would be plenty of places in the world that would accept the people that are under threat of war. That would make it harder to fight wars, if there's less people willing to fight them.

It's just my perspective.