Simple way to wage war: each ruler polls his plebes to find how many would "die for their rule- oops, I mean "country". Once each ruler has a total, they send those willing to die to each other's country, where all of them are executed, as they wish. Then maybe another round. At some point, when each country can find no one left to "volunteer their lives to their rule- oops, I mean "country", the war is over. Leave the rest of us alone.