TURKEY has a habit of converting Christian churches into mosques. So it was a surprise when the prime minister, Ahmet Davutoglu, announced plans for a new church in Istanbul. It will be the first to be built since the founding of Ataturk’s republic in 1923. The church will serve some 25,000 Syriac Orthodox Christians. Decimated by massacres and then by migration to Europe, this group, which once flourished along the border with Syria, has long been campaigning for a church in Istanbul.