The question is: is the EU the symptom or the cause of peace in Europe? According to the Nobel price committee, the EU is the cause. But I have some doubts... a badly governed EU could even spark nationalist resentments instead of containing it.
Certainly, it's a big question that nobody can answer for sure. My point is mainly that saying people have fought and died for this stuff throughout history isn't really an argument against disaster after the fall of the EU.
The American/Allied victory in World War II is the responsible for most of the relatively peaceful world situation. A cooperating West Europe resulted from this.
And a cooperating West Europe existed for years before the EU. Ascribing the peace to the EU seems somewhat revisionist.
The various precursor institutions to the EU go back to 1952.
Sure, but nobody's crediting the six-member European Coal and Steel Community with being the source of European peace.