Rebel infighting has been common during the course of the Syrian civil war. The lack of unity among the rebel groups has consistently undermined their fight against the government of Syrian President Bashar al Assad. In fact, cohesion has been one of the main determining factors of success for the rebels. Jaish al-Fatah, one of the largest and most cohesive rebel coalitions, was formed in March 2015 and immediately began a campaign in Idlib that pushed loyalist forces from much of the province. In contrast, rebel disputes grievously compromised their defense of Aleppo, eventually benefiting the successful loyalist campaign to conquer the city in late 2016.
The latest dispute erupted amid growing mistrust over shifting political alliances, particularly when it comes to foreign backing. Jabhat Fatah al-Sham is under increasing pressure as the United States ramps up its targeted strikes against its leadership and as Turkey toughens its stance on the group. This has made it much more difficult for it to ignore the close links that other rebel groups maintain with the United States and other foreign backers. And the concern is not just that the foreign backers will crack down on certain rebel groups but also that foreign backing distracts from the rebels' primary cause: deposing al Assad.
Turkey, for instance, has nudged many of the rebel groups it backs toward fighting Kurdish and Islamic State forces. It has also encouraged rebel participation in Syrian peace talks with Russia and Iran and has pressured other rebel groups to distance themselves from Jabhat Fatah al-Sham. This has become a problem for Jabhat Fatah al-Sham, given that many of its staunchest rebel allies, including Ahrar al-Sham, have ties to Turkey. In the past, Jabhat Fatah al-Sham and Ahrar al-Sham have reportedly been so close so as to share supplies and equipment. But Jabhat Fatah al-Sham is finding it increasingly difficult to overlook Ahrar al-Sham's connections to foreign governments that are trying to undermine it, even if Ahrar al-Sham did defy Turkey by refusing to participate in the most recent round of peace talks in Astana, Kazakhstan.
To complicate matters further, hard-line Salafist group Jund al-Aqsa, which has long been suspected of having ties to the Islamic State, openly clashed with Ahrar al-Sham in October. The battle undermined a rebel offensive in northern Hama province and threatened to weaken the rebel defense of Aleppo. Eager to contain the damage, Jabhat Fatah al-Sham stepped in to incorporate Jund al-Aqsa members into its ranks, dismantling the group but protecting its members from attack. Ahrar al-Sham, however, claims that Jund al-Aqsa members have continued to carry out targeted assassinations of its members ever since, creating resentment within Ahrar al-Sham's ranks over Jabhat Fatah al-Sham's protective stance.
Though these differences long have been points of contention, they have now led to full-fledged fighting over the past week between Ahrar al-Sham, backed by a number of other rebel groups, and Jabhat Fatah al-Sham. The conflict could seriously hamper the rebellion's ability to defend against a loyalist offensive expected later this year in Idlib. For Damascus, the temporary cease-fire in the country, however partial in practice, and the peace talks are proving beneficial. The pause in violence is allowing the Syrian government to bide its time, enabling it to safely focus on fighting the Islamic State while the rebel forces damage each other.
However pleased the Syrian government may be with the rebel infighting, it still has cause for concern. After numerous failed attempts at rebel unity in the face of loyalist attacks, it was ironically the threat of another rebel group, Jabhat Fatah al-Sham, that finally resulted in what is likely the largest rebel merger thus far. On Jan. 26, the Fastaqeem Union, Jaish al-Mujahideen, the northern branch of Jaish al-Islam, Suqur al-Sham, the Sham Front, and a number of smaller rebel outfits (more than 10,000 fighters all told) decided to merge with the more powerful Ahrar al-Sham and to present a united front against Jabhat Fatah al-Sham. In other words, the dispute between the two most powerful rebel groups seriously affects rebel cohesion, but it is also encouraging substantial mergers. In the following months, it will become clear whether the dispute between Jabhat Fatah al-Sham and Ahrar al-Sham will fatally undermine the rebel cause or if the two can reach an understanding that will ultimately boost their forces and leave them better positioned to face loyalist attacks.