The accusation that Turkey has provided radical Islamists in Syria with weapons, and keeps doing so, continues to be voiced despite government officials' denials. Ankara’s reluctance to get actively involved in the US-led military coalition against the Islamic State (IS) and other radical groups in Syria is also fueling the debate.

Speculation about Turkish aid to radical groups fighting the Assad regime has been re-energized by a trial of gendarmerie officers and prosecutors in Istanbul. They are accused of membership in a “terrorist organization” set up by Fetullah Gulen to allegedly undermine President Recep Tayyip Erdogan and topple the ruling Justice and Development Party (AKP).

Those in custody in connection with this case number about 50 and are being tried for stopping a truck in November 2013 and three trucks in January 2014 on the suspicion that they were carrying weapons to Syria. The operations were ordered by local prosecutors, who were acting on tips.

The trucks turned out to have been chartered by Turkey’s intelligence service (MIT); the government continues to insist that they were carrying humanitarian aid to Turkmens in Syria besieged by the Syrian army.