Despite reports of a possible rapprochement between al-Qaʿida's Syrian branch, Jabhat al-Nusra, and the Islamic State (IS; previously ISIS), the two largest jihadi organizations in the Fertile Crescent, most of their actual fighting to date in Syria, Iraq, and Lebanon has not been coordinated, and in fact these groups see each other as rivals. One exception, however, involved the unsuccessful attempt to free Abu Ahmad Jumʿa, the leader of Liwa Fajr al-Islam (The Dawn of Islam Brigade). The attempted rescue took place just days after Jumʿa had been captured in late July by the Lebanese Army near the Syrian-Lebanese border, where there is a large number of Syrian refugees. This episode, which also resulted in the surrender and incarceration of more than 30 Lebanese soldiers, was a limited instance of cooperation between al-Qaʿida and the Islamic State. More recently, as negotiations between Lebanese authorities and the captors have foundered, refugee family members related to the top leaders of Jabhat al-Nusra, and even the ex-wife and daughter of the Islamic State’s leader, Abu Bakr al-Baghdadi, have been arrested in Lebanon. The chain of events following the capture of Abu Ahmad Jumʿa demonstrates the complexity of the social networks involved in this regional war, and how traditional borders and even factional lines are constantly changing.
Abu Ahmad Jumʿa’s personal background remains something of a mystery. His group first came to light in November 2012 in media coverage that described the key role it had played in supporting the Free Syrian Army's (FSA) capture of the Syrian military’s "Base 26," in the Idlib Province of northern Syria. As the name "Dawn of Islam" would suggest, the militia drifted towards the Islamist groups, whose relations with the FSA grew strained over time. Due to the relatively small size of Jumʿa’s brigade, which was estimated at c. 400 men, it was able to easily move from one battle zone to another. Fajr al-Islam seems to have been one of the few brigades associated with the FSA that continued to fight the Lebanese Shiʿi militia, Hizballah, after the latter enabled the Syrian regime to defeat anti-government forces in the strategic battles over Qusayr in the spring and summer of 2013. Since then, Hizballah and Syrian regime units have managed to largely cut off rebel supplies coming in from Lebanon while driving the rebels out of other towns they had taken in 2012, such as Yabroud. Over the past year, the rebel fighters in the Qalamoun mountains near the Syrian-Lebanese border, consisting mainly of Jabhat al-Nusra commanders and smaller brigades such as Fajr al-Islam, have employed guerrilla tactics against regime and Hizballah targets, while operating from mountain hideouts.
Many of the rebels still fighting in this area, which connects Damascus to the ʿAlawi-dominated Syrian coast, accuse the Lebanese Army of giving Hizballah freedom of passage, while preventing Sunni militants from entering Syria to fight against the Asad regime. To complicate matters, reports indicate that Ahmed Jumʿa has family members among the Syrian refugee population in Lebanon, living just over the border from Syria. As a result, he may have personally been involved in efforts to prevent a full-scale conflict between the rebels and the Lebanese Army, fearing that his family might be placed in harm’s way. This mediation role may have ended, however, when Jumʿa aligned himself with the Islamic State in early July, presumably in order to obtain supplies and to attract fighters to his brigade.  Until then, it appears that it operated under the umbrella of the numerically larger forces of Jabhat al-Nusra in the Qalamoun region. Due to Jabhat al-Nusra’s dominance in the Qalamoun area, the Lebanese Army initially assumed after capturing him that Jumʿa was part of Jabhat al-Nusra. Moreover, Lebanese authorities accused him of helping fighters from Jabhat al-Nusra and the Islamic State in Tripoli, where Lebanese authorities believe these groups are trying to foment a revolt among Lebanese Sunnis in order to establish an Islamist emirate, and to gain access to arms entering Lebanon through Tripoli’s seaport.
Soon after Jumʿa was captured, rebel militias mustered hundreds of fighters to attack the Lebanese Army and Hizballah forces near Arsal. Following five days of heavy fighting, at least 60 militants from Islamic State-affiliated brigades and Jabhat al-Nusra were killed, and a significant number were captured. In addition, Abu Hassan al-Homsi, the leader of a brigade fighting alongside Fajr al-Islam, and in alliance with the Islamic State, was reportedly killed. The costly mission failed to rescue Jumʿa, although it did succeed in killing tens of Lebanese Army and Hizballah fighters and capturing over thirty Lebanese soldiers, who were taken to the rebels’ mountain redoubts.
Military cooperation among relatively small brigades comprising dozens or at most a few hundred fighters each that are alternatively allied with Jabhat al-Nusra and the Islamic State along the Lebanese-Syrian border shows how the factional lines between the two larger groups may be temporarily blurred on the actual battlefield. Yet the history of their initial cooperation and then violent break-up goes back at least to late 2011, when Baghdadi, the Islamic State’s self-proclaimed Caliph, originally sent Jabhat al-Nusra leader Abu Muhammad al-Julani into Syria from Iraq. Initially, the two groups were allied under the leadership al-Qaʿida, headed by Ayman al-Zawahiri, who is believed to be based in the border region of Afghanistan and Pakistan, but the split formally emerged between Jabhat al-Nusra and the IS in 2013 when Baghdadi tried to subordinate Jabhat al-Nusra to ISIS. At the time, many of Jabhat al-Nusra’s foreign fighters had left to join ISIS, which simultaneously wrested control of a number of oil fields and refineries from Jabhat al-Nusra (the latter had taken them from the Syrian regime in the first two years of conflict through joint operations carried out with the FSA).
Defections from Jabat al-Nusra to the IS earlier this year and the Islamic State’s ongoing campaign of violence against it has led to deep rifts and heavy fighting between the two groups. As a result, thousands have died fighting in the eastern provinces of Syria and on both sides of the Syrian-Iraqi border during the past year. Nevertheless, it seems that the relationship between Jabhat al-Nusra and the IS in the Qalamoun mountain area follows a different logic. As forces loyal to the Asad regime have gradually backed rebel fighters into a corner in this region during the past two years, those brigades that are still functioning tend to view themselves as the hard core remnant of the original rebellion and have vowed to fight to the death. Indeed, despite air strikes by the Syrian regime, which continue to take their toll on Jabhat al-Nusra’s fighters and other militias in Qalamoun, al-Nusra’s leader Julani issued a statement in early November claiming that its "brothers in Qalamun are hiding plenty of surprises," and moreover, that "the real battle in Lebanon has yet to begin."
It appears that when push comes to shove, Jabhat al-Nusra and the Islamic State have the ability to cooperate with one another. Yet even when such a tactical alliance exists, it plays out unevenly, as Jabhat al-Nusra appears more sensitive to both public opinion and to the economic incentives offered by third parties, such as Qatar. For instance, while the Islamic State fighters quickly began beheading captive Lebanese soldiers, Jabhat al-Nusra captors waited for several weeks before executing even one prisoner and have been ordered by Zawahiri not to conduct beheadings. After several months without any executions however, Jabhat al-Nusra executed another Lebanese officer they had captured in early December. In a public statement, they referred to their anger over the capture of civilian wives of militants, and in particular the ex-wife of Abu Bakr al-Baghdadi. Today Jabhat al-Nusra is the dominant Islamist militia in the Syrian-Lebanese border area, yet the Lebanese Army's tactic of targeting militants and civilians linked to both the Islamic State and Jabhat al-Nusra may lead these two rival Islamist factions to increasingly coordinate with one another in the fighting along the Syria-Lebanon border. Any move towards broader cooperation between Jabhat al-Nusra and the IS, however limited at the moment, could open up new space for the Islamic State to operate in the rural areas of northern and southern Syria where Jabhat al-Nusra has predominated, which would further add to the challenges facing the “moderate” rebels, who have been caught between jihadist groups and the regime.