Uludere airstrike massacre, INFO was transmitted from American Predator drone.

Uludere airstrike massacre, INFO was transmitted from American Predator drone. (Spiegel).

On a December night in 2011, a terrible thing happened on Mount Cudi, near the Turkish-Iraqi border. One side described it as a massacre; the other called it an accident.

Several Turkish F-16 fighter jets bombed a caravan of villagers that night, apparently under the belief that they were guerilla fighters with the separatist Kurdistan Worker's Party (PKK).

The group was returning from northern Iraq and their mules were loaded down with fuel canisters and other cargo. They turned out to be smugglers, not PKK fighters. Some 34 people died in the attack.

An American Predator drone flying overhead had detected the group, prompting US analysts to alert their Turkish partners. The reconnaissance flight -- which was first reported by the Wall Street Journal in 2012 -- and its tragic consequences provided an important insight into the very tight working relationship between American and Turkish intelligence services in the fight against Kurdish separatists.

Although the PKK is still considered a terrorist organization by the United States and the European Union, its image has been improved radically by its recent success in fighting the Islamic State (IS) in northern Iraq and Syria. PKK fighters, backed by US airstrikes, are on the front lines against the jihadist movement there, and some in the West are now advocating arming the group and lifting its terrorist label.

Documents from the archive of US whistleblower Edward Snowden that 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 US government also provided the Turks with information about PKK money flows and the whereabouts of some of its leaders living in exile abroad. Hmmm....Back in 2012 i already was asking if a US drone gave the info for the strike? It seems i was right.

Related: Turkish PM Erdogan gave order in Uludere air strike, BDP co-chair says