If Britons want to join ISIS, let them go

But to those who argue, in the wake of the girls’ departure, that such measures are necessary – even obvious – I would say: not so fast. Barely a month ago, François Hollande and dozens of national leaders walked through Paris at the head of an enormous crowd in defence of free speech. It has not taken long for that united front and all its certainty to start unravelling. How much free speech can we really bear?

The desirability (or otherwise) of state surveillance and the limits (or not) on free speech are extraordinarily difficult questions. But there are easier questions relating to the three girls from Bethnal Green Academy, questions to which it is possible to hazard answers.

Some have asked, with incredulity, about the appeal to young British girls of Isis. Is it really so hard to discern the attractions of a journey, especially one with an altruistic and religious purpose, to girls who may have led very sheltered lives? It will sound insensitive, but the close embrace of their devoted families may be part of what these girls, and others who have made the same journey, sought to escape. A teenager who regularly accesses dozens of Islamist websites unbeknown to her family is living, to an extent, a secret life.