Not necessarily between the UK and the EU. But I fear that Brexit is the first step in the dissolution of the EU. And I can certainly imagine a future conflict

Not necessarily between the UK and the EU. But I fear that Brexit is the first step in the dissolution of the EU. And I can certainly imagine a future conflict between, say, Austria and a Russia-oriented Hungary. Go look at the distribution of minority nationalities in Europe, and you will see an endless potential for conflict. That was the reality from 111 AD to 1945.