"European borders aren't based on nationality any more than most other borders. They were set by the victors of dozens of wars. If they were based on nationality then they would be fractured even more."
That is kinda bullshit. The borders of germany may have varied based on three wars, but germany wasn't a country until about 150 years ago. And the area that is germany today was based on who spoke german (they had a league dominated by austrians and prussians before that... But austria had it's own empire so didn't join germany until Hitler annexed it in ~1938) Still borders based on nationality - wars have expanded and contracted them, and split the nationality in two - even splitting berlin in two, but the berlin wall came down and East and West Germany reunified - peacefully despite the wars. Germany as we know it today was largely the result of two peaceful unifications. One in 1989 and one in 18??
Czechoslovakia doesn't exist anymore, and not due to any war but due to a peaceful decision to split based on national lies.
Yugoslavia doesn't exist anymore, the state was divided on federal lines based on nationalities and civil war did indeed break out before they managed to settle todays borders - again based on Serb, Croat, Slovenian, Bosnian, Macedonians and most recently Kosovan national identities. (Albanians didn't get much luck in that division, though some would like to see a greater Albania i'm sire)
Scotland voted against independence based on nationality (twice). But within the UK they have been devolving powers fon central government ONLY to nationalities - and the Welsh and English kingdoms have been unified for longer than the US has existed. Other devolution of power to regions within England have been rejected, only The capital cuty has taken more powers for itself...
Likewise Belguim has internal seperation based on language, Walloons, Flemish and Germans each have their own local services and two regional governments.
Sure parts of belguim could have merged with France or the Netherlands or Germany, if not for the several wars. So their borders are based on the Napoleonic wars (i think) and religion ( why Catholic Belgians who speak Dutch didn't want to join protestant Netherlanders who also speak Dutch)
Spain is also divided on linguistic grounds with multiple bational identities; the existance of Poland, Latvia, Lithuania and Estonia are all based on peaceful transitions and mutual languages.
Only in Denmark, Sweden and Norway do i think the borders have been more influenced by war that a common language. Wars where both sides spoke very similar languages but not similar enough.
Contrast this with South America, several different nations with one language (excluding Brazil) Seperated by arbitrary borders which each revolution could define.
The US where state borders are clearly straight lines drawn on a map. The borders with Canada and Mexico were both settled at the end of wars, Spainish speakers fom south of the border cross without changing where the border is. Most of the territory of the US was added while killing or relocating the native inhabitants. Only the Indian territories/reservations remain as language based 'nations'.
Most of Africa and te Middle east had borders drawn in colonial times with the explicit intention of dividing local resistance by mixing populations who would find it harder to unify. The colonial powers didn't want a unifird resistance. Africa has suffered many civil wars and cross border wars as a result. They didn't create their borders, the borders were imposed on them.
Meanwhile, within the EU borders have become less and less important, as we have agreed to the free movement of people and goods, services and capital. The Schengen zone even includes non-EU members who don't want to be bothered with passport controls - Switzerland and Norway. (Though it excludes EU members Britian and Ireland, because the UK decided tey'd rarher be an island onto themselves)
I don't know enough about colonialism in east Asia, but i'm sure i could talk about the Indian sub-continent aswell. Europe is rather different in several ways.