Hmm, methinks this fellow neither too bright nor overly burdened with a knowledge of history.
The current mostly peaceful, monoethnic Euro nation-states descend from sprawling & violent multiethnic empires. They finally got that way via blood and warfare over many years, as many ethnicities did not like living cheek-by-jowl with the stinking, PITA, and uncouth Other Sorts.
Where political boundaries do not coincide with ethnic living spaces, we see much strife and bloodshed. Such as:
* MENA where borders were drawn by colonizers without regard for ethnic settlement
* Africa
* Ukrane
* etcetcetc.
