Islamic State members ask people to go back to the city centre at the Turkish Akcakale crossing gate in Sanliurfa province in June. Turkey has said it was taking measures to limit the flow of Syrian refugees on to its territory. Photograph: Bulent Kilic/AFP/Getty Images

The names of European jihadis who have used Turkey to return to Europe evoke some of the worst tragedies to visit the continent in recent years. The w(...)