“What do a Turkish olive grower, a Danish farmer, and an Irish fisherman have in common?” That sounds like the beginning of bad joke. But it was the question my father posed to me when I visited him in England a couple days after British voters decided to cut ties with the European Union.

His point was that the citizens of the 28 countries (soon to be 27) that make up the EU have very little in common culturally or economically, so it makes little sense to force them together in a confederation.