If Americans think our nation is painfully divided, two statistics from across the Atlantic might put their minds at ease. The first is the percentage of British voters who chose, in a binding referendum last year, to abandon the European Union: just slightly under 52 percent. The other is the number of Catalans who, according to the latest opinion polls, do not wish to declare their independence from Spain: slightly over 50 percent.

At first glance, the two might seem unrelated. Opponents of Brexit complain that the vote to leave the EU was a gesture toward national oblivion, isolating Great Britain—politically, culturally, and especially economically—from the continent. Meanwhile, supporters of Catalan secession argue that, despite its unprecedented autonomy within post-Franco Spain, Catalonia suffers at the hands of an onerous central government in Madrid.