WHEN terrorists in Nigeria organized a secret attack last month, they didn’t target an army barracks, a police department or a drone base. No, Boko Haram militants attacked what is even scarier to a fanatic: a girls’ school.

That’s what extremists do. They target educated girls, their worst nightmare.

That’s why the Pakistani Taliban shot Malala Yousafzai in the head at age 15. That’s why the Afghan Taliban throws acid on the faces of girls who dare to seek an education.

Why are fanatics so terrified of girls’ education? Because there’s no force more powerful to transform a society. The greatest threat to extremism isn’t drones firing missiles, but girls reading books.

In that sense, Boko Haram was behaving perfectly rationally — albeit barbarically — when it kidnapped some of the brightest, most ambitious girls in the region and announced plans to sell them as slaves. If you want to mire a nation in backwardness, manacle your daughters.