If you look closely, you'll see that "fix" is in scare quotes, indicating that dnomad doesn't believe war to be an actual fix, but nonetheless an inevitable consequence of extreme inequality.

I think that's wrong, though. Poor people do not have the resources to wage war. Wars are led by people with resources against other people with resources, with poor people only serving as cannon fodder. That also holds for revolutionary wars, e.g. pretty much any Communist revolution was led by middle-class intellectuals. So I think that inequality might increase criminality and strengthen violent gangs, but it's unlikely to lead to actual war.