Several Turkish F-16 fighter jets bombed a caravan of villagers in December 2011, apparently under the mistaken belief that they were guerilla fighters with the separatist Kurdistan Worker’s Party (PKK). Some 34 people died in the attack. An American Predator drone flying overhead had detected the group, prompting U.S. analysts to alert their Turkish partners.

Documents from the archive of U.S. whistleblower Edward Snowden that Der Spiegel and The Intercept have seen show just how deeply involved America has become in Turkey’s fight against the Kurds. For a time, the NSA even delivered its Turkish partners with the mobile phone location data of PKK leaders on an hourly basis. The U.S. government also provided the Turks with information about PKK money flows, and the whereabouts of some of its leaders living in exile abroad.