Ahh, the modern take on war and nations, the desire for moral superiority and the silly game of pretending there are rules in war.
As hard as it maybe to wrap one's head around this, historically, war was a way to obtain resources, or rather resolve conflicts over resources. Genghis wanted a resource for his horses, he resolved it. If your city was wiped out by him, it was your fault for being weak. You should not expect peace between nations or compassion. Nations are built on stolen land, their borders drawn by blood. We live in a world where nuclear powers maintain balance and modern technology has resolved many of the world 's resource scarcity issues. Our countries are ruled by law, not people. People allowed themslves to be ruled by the most cruel and ruthless in the past because that meant obtaining the most resources for them, even if done on a wh im to satisfy their rulers. People sit back and judge empires from the romans to the british and criticize their morals. It is utterly absurd. I mean, even these days the US invades the middle east and Russia its neighbors for resources. And the terrible thing about democracy is that people think the whole world runs on some system of rules where people's wills and lives matter at a global scale. It sounds nice but that isn't reality. It can be that way in a country but between countries, when you have food shortage your government will not hesitate to wipe out cities and commit genocide on your behalf. My point is that such criticism should be based on reality not on how things should be in an ideal world. The primary directive of any government is not just to secure its borders but the nation itself, whatever that stands for. Be it the elected ruler's will or the monarch's whim.