When a thing looks like another thing, it has characteristics that are similar. So when a rock looks like a toad, the rock will have a shape, texture, color, etc. that are toad-like.

Europe is a continent with a lot of countries that work together on things via the European Union. Many share a common currency, work together economically, while retaining many aspects of national sovereignty. Most have some sort of parliamentary democracy as the basis of their government.

The middle east (today) seems to be more comprised of countries that are independent of each other, with a focus on maintaining what they have, and perhaps spreading their influence. In recent times, They've generally run by Dictatorship, or Monarchy. The concept of a nation seems to be less solid in this area, with ties to religion as a more prominent motivator in the Middle East than we see in general in Europe.

While there is war of some sort happening in both areas, you don't see a lot of Europeans leaving Spain, France, or Lichtenstein to fight in the Ukraine, while fighters from all over the middle east seem to be fighting in the Iraq/Syria area these days.

As I see it, I think there would be some period where the individual states would try to hang on to what they have, and it would look like Iraq after the central government fell, but then we'd eventually form borders more aligned with geography and the will of the population living in those areas, so places like southern Wyoming and Northern Colorado might have a border along the Various rivers and mountain ranges than the arbitrary straight line we have now, or the panhandle of Oklahoma becoming part of Texas or Kansas. Texas, having once been a sovereign nation would probably remain independent, while places like Idaho, Oregon, Washington may combine. Rhode Island would probably seek to join with either Massachusetts and/or Connecticut, for example.

So there's some definition from my perspective. It's not intended to be the only interpretation, but since you asked, there it is.