Thanks for adding to my thought process. I agree, interacting peacefully after the war is a big factor that many leaders don't consider sufficiently.
I'd say most leaders over weight the immediate future to the distant future, and one of the major reasons is that they won't be in power in the distant future so screw the country then... now is all that matters to them. There are very serious downsides to electing new leaders frequently, term limits, etc, that few people have thought about. Like this near-term bias, and also that a nation can't keep its promises and is no longer trustable in negotiations.