It started two weeks ago, when Turkey warned publicly it was preparing for military intervention in Syria, while accusing the US of creating a "terrorist army" (it wasn't referring to ISIS, but US-backed Syrian Kurdish militia YPG). As a reminder, YPG forms a major part of the U.S.-backed campaign to capture Islamic State's stronghold of Raqqa, and whose forces are seen as a terrorist organization by Turkey. The group currently controls a pocket of territory in Afrin, about 200 km (125 miles) west of Raqqa.