LIFEGUARDS in Australia wear them. A mainstream British retailer sells a fashion version of them on the high street. But the “burkini”, a body-covering swimsuit (named with the portmanteau of “burqa” and “bikini”), has been banned this summer by the mayor of Cannes from his stretch of Mediterranean beach, as well as by a dozen other mayors of French seaside towns. In countries with a tradition of liberal multiculturalism, such a ban is greeted by incomprehension, if not ridicule. Within France, however, it enjoys widespread political backing, not just from the far-right National Front but also from the mainstream right and left. Manuel Valls, the Socialist prime minister, has argued that the burkini is “not a fashion item”, but represents the “enslavement of women”. Why are the French so offended by Islamic body covering? The government’s defence of the burkini ban rests on worries about religious tension and public order after recent terrorist attacks, coupled with two underlying principles. The first is laïcité, a strict form of secularism enshrined by law in 1905 after a struggle against authoritarian Catholicism. This principle is supposed to keep religion out of public life, and has been the basis of previous French bans: on the headscarf (and other “conspicuous” religious symbols, including the Jewish kippah and oversized crucifixes) in state schools (in 2004), and the face-covering niqab in all public places (in 2010). The other principle is women’s equality. It may appear bizarre, or frivolous, to argue that women should bare more flesh. But many on the French left in particular regard the need to protect women from a male-imposed doctrine as being at stake—and are willing to put it even before liberty, another founding value of republican France. The logic of the burkini, says Laurence Rossignol, the Socialist women’s minister, is to “hide women’s bodies in order better to control them”.

Over the years, such efforts have long been met with dismay, if not derision, outside France. When the French began to debate a ban on the burqa in 2009, for instance, Barack Obama declared in Cairo that Western countries should avoid “dictating what clothes a Muslim woman should wear” under “the pretence of liberalism”. Some civil-liberties groups within France have tried—but so far failed—to get the burkini ban overturned in the courts. Yet French governments bristle at the notion that their various attempts to defend laïcité amount to intolerance or an infringement of the freedom of expression. They may note that in 2014 the European Court of Human Rights upheld France’s burqa ban. What outsiders fail to understand, the French argue, is that such body wear is not just a casual choice but part of an attempt by political Islamism to win recruits and test the resilience of the French republic. Mr Valls dismisses as naive those who see it as being no different than a wetsuit. The burkini, he says, is part of a “political project”, and complacency plays into the hands of Islamists.

The difficulty is that, after a series of deadly terrorist attacks over the past 18 months, France is in a state of heightened tension. Perceived provocations on both sides are amplified. It is not just civil-liberty activists who consider the mayors’ ban excessive, or stigmatising. Some French scholars of Islam, such as Olivier Roy, consider it “absurd” to conflate the burkini with hard-line Islamism, not least because the latter would not permit women to bathe publicly in the first place. Politicians, though, are unlikely to cede ground. The nature of French identity is likely to feature prominently in next year’s presidential election. Some contenders, such as Nicolas Sarkozy, a centre-right former president, argue that the Muslim veil should be banned on the campuses of state universities. France looks set to defend, if not tighten, its strict approach to head-covering.