This is an interesting Stratfor article:
**The Islamic State is fending off attacks from all sides in Syria, and there are growing indications that a Turkish ground invasion could add to the group’s list of concerns. The Turks are determined to clear the Islamic State from a corridor of land stretching along the Syrian side of the Turkey-Syria border. In what could be a sign of this intent, Turkish minesweeping vehicles have started clearing mines along a section of the border near the Syrian town of Jarabulus, which the Islamic State controls. According to Stratfor sources, Russia and the United States have discussed the plan, and Russia has agreed not to obstruct Turkey’s efforts so long as Ankara does not try to expand the buffer zone to the Mediterranean Sea — a stipulation Turkey has reportedly acquiesced to. Our sources also said liaison officers from Turkey, Russia and the United States will coordinate with one another to prevent cases of accidental fire or, in the event that they do occur, to avoid any escalation between Turkish and Russian forces.
As Stratfor has noted, Turkey has long wanted an international operation to clear the Islamic State from northern Aleppo, and its plan to establish a buffer zone along the border may be the first step toward achieving its goal. If such an operation occurred, it would deal a heavy blow to the Islamic State, which recently launched a suicide bombing against the Turkish capital. It would also strengthen the rebels in northern Syria, in turn preventing the Kurdish People’s Protection Units (YPG) from expanding their reach westward. Finally, an international operation would likely draw the United States deeper into the Syrian conflict — a boon for Turkey, which does not want to go it alone.
Until now, though, Turkey’s plans for Syria have been greatly complicated by Russia’s intervention in the conflict, and Moscow has continued to frustrate Ankara’s ambitions since Turkey shot down a Russian Su-24 warplane in November 2015. For instance, the Russians have reinforced their air defense assets in Syria, and in a Dec. 17 interview Russian President Vladimir Putin dared Turkey to fly over Syrian airspace, implying that the aircraft would be shot down if it did.
Despite the considerable risks, Turkey may decide to move forward with its operation anyway. Assaults by Russia-backed loyalists have stretched thin the Syrian rebels allied with Turkey, and the Islamic State has turned its gaze toward Turkey’s cities. Meanwhile, the Kurdish YPG is making headway in the territory west of the Euphrates River. Each of these developments could encourage Turkey to take a more active role in the Syrian conflict, even it means risking a clash with Russia.
Still, that does not mean that Ankara, with Washington’s help, is not trying to reach an understanding with Moscow, at least in terms of setting up deconfliction procedures to avoid clashing with each other in the Syrian warzone, which is rapidly becoming crowded. On Jan. 22, U.S. Vice President Joe Biden and U.S. Assistant Secretary of State for European and Eurasian Affairs Victoria Nuland plan to travel to Istanbul for high-level talks with Turkish officials. The United States could use this opportunity to try to bring Turkey back into talks with Russia over the Syrian conflict. However, even if both sides set up deconfliction procedures, they cannot guarantee that miscalculation and escalation will not take place in an atmosphere rife with mistrust and suspicion.
Turkey has already begun to ramp up its artillery strikes along its border with Syria to help its rebel allies and to destroy Islamic State targets. This could indicate an effort to soften enemy defenses ahead of a Turkish ground incursion once minesweeping operations have been completed. An invasion could theoretically occur at any point along the Islamic State-controlled portion of Turkey’s border with Syria, but if it begins at Jarabulus, where Turkey is clearing mines, it would have to be mostly carried out by Turkish forces. The nearest Syrian rebel lines are nearly 100 kilometers (62 miles) away, and no coalition ground troops are present in Turkey to offer support.
The threat of an impending Turkish ground offensive is only one of many confronting the Islamic State in northern Aleppo at the moment. The group is already grappling with a three-pronged assault on its territory in the area. From the east, the Kurdish-dominated Syrian Democratic Forces have crossed the Euphrates River, despite Turkey’s opposition to the move, and they are now advancing westward toward the Islamic State-held town of Manbij. From the south, Syrian loyalist forces backed by Russian airstrikes are advancing toward the city of al-Bab. And from the west, rebel forces predominantly from the Turkey-backed Mare Operations Room are advancing eastward along the Turkey-Syria border, looking to gain ground held by the Islamic State. The possibility of a ground invasion by Turkey could make the Islamic State’s fight for territory even more difficult, albeit at the risk of also complicating the operations of the other parties involved in Syria’s civil war. **