In August, rebel groups in northern Syria began to discuss unity after a successful battle to break a week-long siege around Aleppo. Today, the northern rebels are a fragmented lot along three fronts. These fronts unravelling concurrently put to the test the three most powerful jihadist groups in rebel-held Syria, which do not include ISIL.

The first divergence happened when a rebel alliance was formed in August to take on ISIL in Aleppo’s eastern countryside, with air support from the United States and Turkey. A month before, Jabhat Al Nusra had changed its name to Jabhat Fateh Al Sham to further integrate with the insurgents, and led an effective military and media campaign to present itself as a capable force to unite and conquer. It sought to use the momentum of breaking the siege in Aleppo in August to bring some of the opposition’s most powerful forces into its fold.

The anti-ISIL battlefield provided the Free Syrian Army and Islamist groups with a new front and relevance. The regime’s second siege of Aleppo in September further took the steam out of the merger discussions.

By then, the northern rebels had divided on to two battlefields. The development worried JFS, because it diverted resources from the Aleppo battlefield. Differences over the opening of that front grew, to the point that JFS issued a fatwa demanding that its close military partner Ahrar Al Sham review an earlier fatwa supporting the rebels’ collaboration with the Turkish backed Operation Euphrates Shield against ISIL.

A third front came about last week, the implications of which could widen the two-front divergence. Clashes between Ahrar Al Sham and Jund Al Aqsa, another key jihadist group, erupted last week in northern Hama and adjacent southern Idlib after a year of tension. In a fatwa, Ahrar Al Sham accused Jund Al Aqsa of discreetly working with ISIL and engaging in an underground campaign of targeting rebel commanders.

Ahrar Al Sham received support from various rebel forces to declare war against the group, known to exhibit extremist views against the rebels, similar to those of ISIL before it. Ahrar Al Sham and its allies seemed to have finally decided to uproot the group, but clashes abated after reports emerged that Jund Al Aqsa pledged allegiance to JFS.

Jund Al Aqsa’s smart move to pledge allegiance to JFS created an awkward situation for the close allies, JFS and Ahrar Al Sham. The latter two stand to lose in the long term, but the episode appears to be more perilous for Ahrar Al Sham.

Contrary to some reports, the clashes between the two groups are not ideological. They are rooted in a turf war between the two that came to a head in October last year, when the rebels wanted to open a front in Hama. Jund Al Aqsa rejected the notion of fighting ISIL there and started to focus on Hama, as other groups focused on Aleppo and northern Latakia.

Ahrar Al Sham accused the group before of collaborating with ISIL, but it still did not fight it until Jund Al Aqsa started to advance militarily in Hama. The direct trigger of the latest clashes was Jund Al Aqsa’s takeover of a town in southern Idlib.

Even though Ahrar Al Sham accused Jund Al Aqsa of being an ISIL enterprise, it pointed only to some members as ISIL-type “extremists” – deliberately chosen to legitimise its war. Similar accusations are often levelled against Ahrar Al Sham itself. If Ahrar Al Sham views the existence of ISIL-type extremists within a group’s ranks as a cause of attacking it, it puts itself and its defenders in an awkward position, as the group has many of that type. Some of them left the group last month following an approval of their participation in the Turkish-backed operation.

In the same vein, if those extremists have now joined JFS, will Ahrar Al Sham cease to cooperate with a group that has them in its ranks? Ahrar Al Sham has already accused JFS of providing protection to ISIL-type extremists, echoing a similar accusation against JFS’s former incarnation, Jabhat Al Nusra, when it protected ISIL during the rebels’ clashes with ISIL in January 2014. Syrian activists point to a similar pattern. The episode might increase tension between JFS and Ahrar Al Sham and weaken the rebels militarily. But it also offers an insight into what lies ahead for Ahrar Al Sham, especially with regard to JFS’s attempt to co-opt it.

Ahrar Al Sham has hinted that it seeks to dissolve Jund Al Aqsa, rather than to eradicate it. After reports that the latter joined JFS, Ahrar Al Sham rejected the wholesale allegiance and demanded instead that members not involved in the bloodletting could join JFS as individuals, not as a group.

The same fate might be exactly what JFS envisions for its co-optation of Ahrar Al Sham. Fadhel Al Sheikh, who broadcasts reliable inside news about jihadists in Syria, pointed to this possibility in a recent social-media post. He accused JFS of planning to induce large-scale defections inside groups that oppose the merger with it, including Ahrar Al Sham.

Abdullah Al Muhaysini, a Saudi jihadist close to JFS, also explicitly threatened to organise a collective call for defections if the groups do not merge with JFS. As the Jund-Ahrar clashes raged last week, a JFS media official was also clear that the aim of the clashes was to disintegrate Jund Al Aqsa without completely eliminating it.

JFS is unlikely to pursue full disintegration of such groups, because it will continue to need friendly groups to embed itself in local communities. Yet, its strategy also centres on ensuring that such groups are subordinate to it, sooner or later. Whether JFS actually has such a plan, clashes over the past few days provide a blueprint for how that might happen in the long term. And that tells an important tale: the fracture of the groups fighting in Syria might weaken the rebels, but hard-line factions have a way of winning.

Hassan Hassan is a resident fellow at the Tahrir Institute for Middle East Policy and co-author of ISIS: Inside the Army of Terror

On Twitter: @hxhassan