In Stratfor's 2018 Annual Forecast, we said that Syria's Kurds would be central to military activity in the country this year. Now, Turkey has launched an offensive against the Kurdish militias in northern Syria, and it will continue efforts to divide and weaken those forces, even if other powers in the region disapprove.
Following at least two days of heavy bombardment and shelling, Turkish forces and their Syrian rebel allies have begun the ground phase of their invasion into the northern Syrian region of Afrin — dubbed Operation Olive Branch. The advance against the Kurdish People's Protection Units (YPG) that control the region has so far been slow but methodical, inhibited by the area's difficult and mountainous terrain. Nevertheless, as of Jan. 22, Turkey and its allies have already seized a number of strategic hilltops, mountain peaks and villages.
The majority of the advancing forces have come from north of Afrin, and the predominantly rebel formations on the eastern side of the battle zone have now launched their own assaults on the Kurds. Most of the difficult terrain is concentrated around the current frontlines, meaning that if Turkey and its allies accomplish their initial objectives they will have an easier task advancing farther.
But Turkey is already thinking beyond the battle for Afrin. The country has continued to stress its desire to push the YPG out of the city of Manbij, which lies east of Afrin. And the willingness of Turkish forces and their rebel allies to move into Afrin despite initial resistance from Russia introduces the possibility that Ankara might attempt something similar in Manbij, despite possible opposition from another major player in the region, the United States.
There are, however, differences between Turkey's Afrin and Manbij approaches. While Moscow certainly would have preferred that Ankara not launch its Afrin campaign, given its attempts to integrate the YPG into Syrian peace talks, Russia views its strategic relationship with Turkey as far too important to sacrifice for the sake of Afrin. Manbij, on the other hand, is currently controlled by the Syrian Democratic Forces (SDF). And though the YPG is part of the SDF, the coalition involves many other groups and is at the very center of the United States' strategic approach to Syria. With the SDF, the United States aims to build a force that can prevent the rebuilding of the Islamic State or any similar groups, establish a counterweight to the Syrian government in Damascus and contain growing Iranian power.
Thus, if Turkey were to advance on Manbij or other SDF-held territory, Washington would be obligated to intervene or else risk collapsing the foundation of its Syrian strategy — its relationship with the SDF. And since the Turks are eager to avoid any real resistance from the United States, Ankara is unlikely to echo its moves in Afrin with an outright military operation in Manbij — though there is a chance that the involved parties could reach a diplomatic solution.