Turkish armed forces have moved towards Jarabulus, ostensibly to take the Syrian town from the Islamic State. But - at the same time - the assault seems calculated to prevent the Syrian Kurdish forces from creating a statelet in northern Syria, what the Kurds calls Rojava. These Syrian Kurds in alliance with Arab and other fighters had - as the Syrian Democratic Forces - seized Manbij. This opened up the possibility to push for a contiguous Syrian Kurdish region.
No wonder that the Syrian Kurdish leader Saleh Moslem responded to the Turkish assault harshly, "Turkey is in Syria