Nation states are a thing that is now so prevalent it's hard to even think about them. Nations, nation states & nationalism are such core political institutions

Nation states are a thing that is now so prevalent it's hard to even think about them. Nations, nation states & nationalism are such core political institutions that we think of them today as synonyms to "polity." Obviously the nation's is the polity and the polity is a nation state. The whole world is carved into nation states politically today. It's so prevalent that we forget that it's new. Less than 100 years ago it was less than half the world. Before that it was rare. In any case, I disagree that war is what made nation states. War always existed and nation states haven't always been the dominant type of state. I think democracy/liberalism/republicanism is a more likely culprit. The timing lines up, and so does the political group psychology.