It would be hard to find swimwear skimpy enough to cause offence on the French Riviera. It turns out that people are more easily shocked by the idea of covering up.

With emotions still running high after the attacks on Bastille Day crowds in Nice and on a Normandy church, the mayor of Cannes instituted a ban on swimming at the city’s beaches in dress that could be held incompatible with morality, secularism, hygiene or safety — as well as anyone wading in fully clothed. No one was in any doubt of what he had in mind: the full-length, hooded two-piece for Muslim women, known as the burkini. Other local mayors followed suit, sparking fierce debate and legal challenges that have yet to be resolved by France’s supreme court.

The controversy may seem frivolous but it encapsulates the difficulties French society is grappling with as it confronts the threat of jihadism. In a country that bans the veil from schools and the full-face version from public spaces, there is a widespread discomfort with visible expressions of faith. But this should not lead people to conflate strong religious conviction with violent extremism.