When Hasan Erol and other parents learned that their children’s school would be converted to specialise in Islamic education, they hit the streets. Yeşilbahar Middle School is among five in Istanbul’s staunchly secular district of Kadıköy to have been earmarked for conversion into imam-hatips, religious schools in which 20% to one-third of hours are dedicated to Sunni Islamic study. “They want to transform this area into something else,” says Erol, whose 13-year-old son goes to the school. “They want to make it more conservative by bringing imam-hatips here.” Yeşilbahar was spared. Authorities relented in the face of protests and a...