A key ally in the American war against Islamic State has been the Syrian Democratic Forces (SDF), which now control, with the help of roughly 2,000 U.S. troops, the northeastern third of the country. To Ankara’s great consternation, the SDF is led by the YPG, a Kurdish militia that is for all intents and purposes an extension of the PKK, a Kurdish terrorist group operating within Turkey’s borders. The resulting Turkish-Kurdish tensions, argue Merve Tahiroglu and Andrew Gabel, leave both parties likely to turn to the Syria-Iran-Russia axis to broker the conflict—unless Washington uses its leverage:
Politically, Ankara’s foremost fear is the emergence of an autonomous Kurdish region bordering Turkey’s own Kurdish-dominated southeast. . . . [S]hifting more power to the SDF’s non-Kurdish elements would dilute the influence of nationalist Kurds within the group, allowing both local Arabs and Turkey to stomach the SDF’s existence more easily. . . .
Turkey would prefer to create a safe zone in northeastern Syria, in which the Turkish military would occupy Kurdish population centers and clear them of YPG militants, as it did in the [Syrian] Kurdish canton of Afrin in early 2018. Because the United States is unwilling to support such an operation against its Kurdish allies, Ankara has turned to Russia for help.
Realistically, however, the United States is the best-positioned actor to ensure that northeastern Syria does not become a PKK sanctuary. Iran, Syria, and Russia have a long record of employing Kurdish groups as proxies against Turkey, and are ready to do so again. The United States, by contrast, is already working with Ankara to move certain YPG militants away from the Turkish border, and in the long term it could use its leverage over the YPG to lure the group away from the PKK. [Above all], Washington should condition further U.S. support for the YPG on the group’s continued restraint toward Turkey. . . .
In addition to pushing the YPG away from the PKK, the United States should attempt to marshal northeastern Syria’s valuable natural resources to deepen Turkey’s interest in the stability of the region. The SDF now controls almost all of Syria’s oil fields, which, if properly leveraged, could foster peace-building efforts between the Syrian Kurds and Turkey.
There is precedent for such an arrangement: at first, Ankara fiercely objected to the existence of the autonomous Kurdistan Regional Government in Iraq. Today, Turkish businesses are all over Iraqi Kurdistan, and Erdogan facilitates a controversial oil trade between [this region] and Israel. Erdogan is an opportunist and may well accept an SDF-controlled zone in Syria so long as he is a primary outside beneficiary of its resources.