[netcan]

Looking at the nation-state idea via the perspective of the US is probably going to be misleading. The American countries are former colonies where the colonists (as opposed to the colonized) formed countries and the nations were formed from those countries.

European nations mostly predate their states (at least in the minds of the people). You can be Irish-American in the US. That is a different kind of a thing to German-Italian. The US version is a nod to heritage. The European version is an admission of a schism. It means German (nation) citizen of Italy. In modern times immigrants do assimilate but this is probably following the US' example. By tradition, citizenship does not imply nationality. You can live in Japan, that doesn't make you (or your grandchildren) Japanese. The Basques are not "Spanish." Kurds are not "Turkish" or "Iraqi" or "Arab." Israel is probably the country that takes the nation state idea most literally.

I actually think the US is the most stable model, because of its flexibility. But, nothing has lasted forever so far.