Why Turkey Went to War in Syria

The United States may finally have a professional military ally against the Islamic State in Syria. The Turkish-led assault on the northern Syria town of Jarablus, which was held by the Islamic State for two-and-a-half years but was re-captured Wednesday with little resistance, will shape the war on the extremist group to Washington’s advantage.

Turkey entered the Syrian war directly for the first time Wednesday morning, sending tanks and special forces to support a rebel offensive on the Islamic State’s only remaining stronghold on the Turkish border. U.S. aircraft also backed the offensive, providing close air support against Islamic State targets — a crucial indication that the Turkish intervention had received Washington’s acceptance. Rebels declared victory within hours, suffering no significant casualties. Turkey has thus quickly achieved its immediate objective of taking Jarablus and has now signaled its attempt to push westward to “cleanse” the border area of the Islamic State.

The campaign itself may launch a new era of U.S.-Turkish cooperation in Syria. It’s true that Ankara’s motives for directly entering the Syrian war do not cleanly overlap with Washington’s and are in direct conflict with those of the Kurdish Democratic Union Party (PYD), which is a U.S. ally in the fight against the Islamic State but is considered a terrorist group by Turkey. Overall, however, Wednesday’s events mark a change for the better for the United States, its alliance with Turkey, and the war on the Islamic State.

Every actor in the Jarablus operation is fighting for its own reasons. Turkey certainly sought to weaken the Islamic State, which has shelled Turkish territory and carried out a series of terrorist attacks — including a suicide bombing in the southern city of Gaziantep just last weekend, which killed 54 people at a wedding. More importantly, Ankara is responding rather belatedly to territorial acquisitions in northern Syria by the PYD-dominated Syrian Democratic Forces (SDF), which aims to connect different “cantons” to form a contiguous Kurdish territory along the Turkish border. As Turkish Prime Minister Binali Yildirim said Wednesday, Turkey will not accept a Kurdish entity on its border.

But why now? The SDF has been expanding for months, and the Turkish response had been rather muted until Wednesday. Ankara may have hoped the United States, which supports the SDF, would pressure the group to respect territorial red lines, such as staying east of the Euphrates River. This, however, did not happen, as the SDF crossed the Euphrates and eventually took the town of Manbij on Aug. 12 and seemed intent on continuing west to link up with the farthest Kurdish canton in Efrin.

The SDF’s growing momentum seems to have changed Ankara’s calculations, leading to the Jarablus operation. Turkey had already been fighting a rebel proxy war to clear other border areas of the Islamic State and preempt SDF expansion, using local militias but resisting the deployment of Turkish troops into Syria. In taking Jarablus, groups including the Sultan Murad Division, Faylaq al-Sham, Liwa al-Mutasim, and the Nour al-Din al-Zenki Movement were moved from other rebel areas farther west, through Turkish territory, and over the border into the Jarablus fight.

This is Turkey’s most dramatic move in its otherwise inconsistent war on the Islamic State, and it could provide a blueprint for cooperation with the United States going forward. Washington has been hesitant to ally with Turkish-backed rebel groups focused on fighting Damascus, fearing it could be dragged into a war against President Bashar al-Assad’s regime. This has left the United States heavily dependent on the PYD, an affiliate of the Kurdistan Workers’ Party (PKK) — a U.S.-designated terrorist group — and a sworn enemy of Turkey.

The United States desperately needs an ally that can deliver results against the Islamic State, work with local Arab citizens who are suspicious of Kurdish groups, and serve as a strategic international partner rather than a local militia. While Turkey was focused exclusively on defeating the Assad regime and containing the PYD, none of this was possible. But if Ankara calculates that playing a central role against the Islamic State is its best chance to bolster viable Arab partners in northern Syria — while countering the possibility of a united, hostile Kurdish entity — that would change.

The Jarablus operation is therefore the culmination of a strategic Turkish adaptation, PYD overreach, and U.S. eagerness to expand its operations and partners against the Islamic State. Turkey will leave the town in rebel hands, though it may also choose to keep its own troops there to deter or defend against Islamic State counterattacks. If Turkey and its allies can hold it, Jarablus could serve as a springboard for further Turkish-backed expansion of an anti-Islamic State buffer zone. This will cement a new partnership between Turkey and an array of Syrian rebels, with U.S. backing.

These dynamics have potentially enormous implications for the war in northern Syria. They may raise Turkish-PYD tensions in the short term, which the United States will have to manage and factor into its anti-Islamic State strategy. On balance, however, Washington has little choice but to embrace Ankara, a NATO ally, over a controversial militia that is Turkey’s enemy.

Having Turkey as a full-fledged partner in the anti-Islamic State fight also will give Washington greater leverage with its Kurdish allies. In Ankara Wednesday, U.S. Vice President Joe Biden called for Kurdish forces to withdraw from areas west of the Euphrates, which is the very region Turkish-backed rebels hope to expand into. Kurdish forces will likely have little choice but to comply — or risk losing U.S. military support. Thus, a curb on Kurdish expansion may actually de-escalate Turkish-Kurdish tensions, so long as the United States remains engaged in the war.

If built upon, the Jarablus operation could lay the basis for much-needed U.S.-Turkish cooperation, facilitate an Arab-Kurdish balance of power in northern Syria, and substantially strengthen the war on the Islamic State. And if Washington and Ankara remain closely engaged, they should be able to secure the border area. South of that strip of land, however, things get complicated, as the rebels will eventually run into PYD and regime forces. Their respective foreign backers — Turkey, the United States, Russia, and Iran — will have to work very hard to avoid an escalation. For now, however, Washington has plenty to gain from Ankara’s newfound enthusiasm and aggression against the Islamic State.

Photo credit: BULENT KILIC/AFP/Getty Images