On Tuesday, September 9, an explosion ripped through a building in Idlib in northwest Syria, killing dozens of people. While speculation persists about the source of the explosion, its results are now clear: the blast wiped out most of the senior leadership of the Ahrar al-Sham Islamic Movement.

Confirming the news, the Islamic Front—an Islamist umbrella organization which Ahrar al-Sham helped create in late 2013—has issued a brief statement in Arabic and English, reproduced here in full:*

I SEEK REFUGE IN ALLAH FROM SATAN

Who, when disaster strikes them, say, "Indeed we belong to Allah, and indeed to Him we will return." Those are the ones upon whom areblessings from their Lord and mercy. And it is those who are the [rightly] guided.

Among the believers are men true to what they promised Allah. Among them is he who has fulfilled his vow [to the death], and among them is he who awaits [his chance]. And they did not alter [the terms of their commitment] by any alteration–

The Islamic Front gives the Muslim world the good news of the martyrdom of the head of Ahrar al-Sham Islamic Movement (Head of the Political Bureau of the Islamic Front) Hassane Abboud (Abu Abdullah al-Hamawi) and some of his companions: Abu Yazen al-Shami, Abu Talha al-Ghab, Abu Abdulmalek al-Sharei (head of the Islamic Sharia Council of the Islamic Front), Abu Ayman Al-Hamwi, Abu Ayman Ram Hamdan, Abu Sariya al-Shami, Muhibbeddin al-Shami, Abu Yusuf Binnish, Talal al-AhmadTammam, Abul-Zubeir al-Hamawi, Abu Hamza al-Raqqa and several other leaders of Ahrar al-Sham.

They died through a car bomb while they were meeting in rural Idlib. They died after years of Jihad against the Taghut [tyrant] of the Levant. May Allah grant them mercy and accept them as martyrs!

*Some Arabic names have been adjusted for consistency in spelling.

Top leaders killed

The list of dead reads like a who’s who of Ahrar al-Sham leaders. Not only do the fallen fighters include the founder and emir of the group, the scholar-warrior Hassan Abboud, better known by his nom de guerre Abu Abdullah al-Hamawi. There is also the top military commander Abu Talha al-Ghab, the religious ideologues Abu Abdelmalek al-Sharei and Abu Sariya al-Shami, Abul-Zubeir al-Hamawi who led the main Ahrar al-Sham faction in Hama, and so on.

Only a few of the publicly known faces of the group seem to have survived the blast, including the veteran Islamist ideologue Mohamed Ayman Aboul-Tout (alias Abul-Abbas al-Shami), the Idlib-born Islamic judge and former spokesperson Mohammed Talal Bazerbashi (alias Abu Abderrahman al-Souri), the international relations official Abu Mustafa al-Absi, and a founding leader called Khaled Abu Anas from Saraqib in the Idlib Province.

Of course, there may still be influential but unknown figures left who could step into the void and prevent Ahrar al-Sham from fracturing. But if not, it seems that one of Syria’s most important rebel groups has been decapitated.

Why Ahrar al-Sham matters

Ahrar al-Sham was one of the first armed movements to emerge in Syria, and it has long appeared to be one of the best organized. Its foundations were laid in Idlib and Hama in May-June 2011 by former Islamist political prisoners and Iraq war veterans held in the Sednaya Prison north of Damascus, after their release from jail in early 2011. These men espoused a stark Salafi ideology calling for a Sunni theocracy in Syria. Funding was quickly secured from foreign sympathizers such as Hajjaj al-Ajami and other Gulf clerics, many of whom were linked to the Salafi Umma Party in Kuwait.

Ahrar al-Sham never made any pretense of belonging to the so-called Free Syrian Army (FSA), an umbrella term for rebels backed by some Western and Gulf countries. But while it was in some ways close to the al-Qaeda movement, and some leaders had worked with Osama bin Laden in Afghanistan, Ahrar al-Sham was not quite a transnational jihadi group either. For one thing, it consistently stated that its battle was limited to Syria and avoided the aggressive minority-baiting common among the more radical jihadis. Ahrar al-Sham also sought to ally pragmatically with all groups fighting Syrian President Bashar al-Assad’s government—certainly including al-Qaeda’s Nusra Front, but also Western-backed FSA factions. Emerging as a central pillar within the wider Syrian Islamist landscape, Ahrar al-Sham helped engineer a large rebel coalition called the Syrian Islamic Front (SIF) in December 2012 and then grew by absorbing most of its smaller member groups. A year later, the enlarged Ahrar al-Sham movement co-created a successor to the SIF, the still-existing Islamic Front.

It was, in short, the missing link between radical Salafi-jihadism and the type of mainstream and Syrian nationalism-infused Islamists that Western and Gulf state powers preferred to work with—a powerful “swing voter” in the struggle over the ideological direction of Syria’s insurgency.

Closeted pragmatists

As the rebellion grew more starkly, Islamist and moderate factions crumbled, and Ahrar al-Sham for some time seemed to be tipping to al-Qaeda’s side. After the Lebanese Shia faction Hezbollah helped Assad to recapture the city of Qusayr in May-June 2013, Abboud seemingly threw caution to the wind and launched into a harsh sectarian and anti-Shia rhetoric that had not previously been heard in official addresses by Ahrar al-Sham.

But as the opposition’s fortunes waned and new competition emerged in the form of the Islamic State (IS, formerly ISIL or ISIS), an ultra-radical splinter faction from al-Qaeda, Ahrar al-Sham again started to look for alliances within the FSA camp. That development was probably encouraged by the fact that it appeared to have grown dependent on Qatari and Turkish support, by late 2013 if not earlier, and by the growing Saudi role in the insurgency; Saudi Arabia’s preference was for more pliable anti-Islamist factions or pro-Saudi Salafis.

In early 2014, after major conflict had erupted between the Islamic State and other factions in Syria, Abboud and his fellow commanders began making ever more moderate noises. Having lost access to certain funding sources, allegedly after U.S. pressure on Qatar and badly mauled by the Islamic State in Idlib and Aleppo, the Ahrar al-Sham leadership belatedly sought to reenter the rebel mainstream.

Without ever renouncing their stalwart Salafism or their opposition to parliamentary democracy, the Ahrar al-Sham leaders began making curiously un-Salafi statements, declared their intent to protect religious minorities, struck alliances with more mainstream Western and Gulf backed groups, and issued oblique warnings to the Nusra Front (although perhaps partly because the Nusra Front had in turn responded to the Islamic State’s challenge by growing more rigid and radical). A few weeks ago, Ahrar al-Sham even took the unprecedented step of joining the Revolutionary Command Council, an FSA-style joint leadership spearheaded by groups openly in thrall to the United States and its allies.

A crucial moment

The gutting of Ahrar al-Sham’s leadership will have major ripple effects in the opposition. Some of the dead leaders were also top-ranking figures within the larger Islamic Front alliance. The Islamic Front has been in decline for some time and recently, several of its member factions have begun seeking new allies outside the Front’s framework. Unless Ahrar al-Sham somehow manages to recover and sustain its relevance as a major Islamist faction, the Islamic Front may now be beyond repair.

Militarily, the effects may not be immediately visible. While the death of so many leaders is likely to disrupt activity, fighters aren’t likely to instantly throw away their weapons and go home. But they are likely to begin to drift into the orbit of other factions, if Ahrar al-Sham appears to be a spent force or fails to lead, equip, protect, and finance them. Such leaderless fighters can spill either way. Some may opt for FSA-aligned factions such as the Mujahideen Army, but more committed Salafis may find the Nusra Front more to their liking. Others still could decide to join the Islamic State.

That’s particularly the case in Aleppo, where the remaining defenders in the rebel-held eastern half of the city are on the verge of being fully encircled by government forces, just as the Islamic State pushes in from the east. Now, Abu Hamza al-Raqqa and Abu Yazen al-Shami—both of whom are former leaders in the Islamic al-Fajr Movement, an Aleppo-based faction that merged into Ahrar al-Sham in early 2013—are dead. They have led Ahrar al-Sham forces in Aleppo and acted as the public faces of much of its activity there. Now their disappearance could leave the Ahrar al-Sham contingent in East Aleppo rudderless and easy prey for both the regime and other groups.

In the larger scheme of things, such a weakening or fracturing of Ahrar al-Sham would also affect the rebellion’s links (or lack thereof) to al-Qaeda. If Ahrar al-Sham vacates the crucial middle ground between the Nusra Front and the mainstream Islamist and FSA factions, or if it is reduced to irrelevancy, others may step into the breach—but it is equally possible that the gap will remain unfilled, cementing the Nusra Front’s isolation from the “mainstream” rebellion.

The smoke has yet to clear after the explosion that killed Hassan Abboud and his fellow Ahrar al-Sham leaders, but the effects of their sudden disappearance will be felt for a long time yet.