by Jennifer Cafarella
The ISIS tactics that have achieved devastating success in Iraq continue to be employed on the Syrian front. In Deir ez-Zour province, ISIS has consistently leveraged carefully targeted suicide operations alongside tactical shaping operations tailored to create conditions of battle conducive to an ISIS advance. These preparatory efforts have focused primarily on weakening or neutralizing rebel commanders and key infrastructure, in addition to coercing local armed groups into submission. Using small contingents of fighters, ISIS has steadily advanced onto key towns and terrain within Syria’s oil-rich Deir ez-Zour province, increasingly leveraging local rebel groups as force multipliers and capitalizing on local submission in order to establish zones of control from which to advance on its primary objectives. On the heels of a number of significant ISIS gains in the province, as well as in Iraq, the declaration of a so-called “Islamic Caliphate” on June 30 has seen ISIS control quickly expand over nearly the entire southern countryside of the province as a cascade of rebel groups have folded under ISIS pressure and pledged bay’ah [allegiance] to the leader of the newly-established caliphate or simply “Islamic State.” The strategy of subsuming local and tribal elements into ISIS command is one that has been leveraged consistently throughout its Iraq and Syria campaigns, and has conferred effective territorial control over the majority of the key supply routes and oil fields in southern Deir ez-Zour province.
Reports of defections to ISIS in Deir ez-Zour increased in the wake of the successful ISIS campaign in Iraq. ISIS encouraged such defections by distributing statements in the Deir ez-Zour countryside that rejected the accusation that ISIS fighters are “kharijites,” or extremists, and reassured rebels that they would not be unjustly labeled “infidels.” In addition, ISIS released a statement on June 26 specifically calling for the repentance of rebels in the JN stronghold of al-Mayadin. The combination of these overtures and increased ISIS strength conferred by its windfall weapons seizures in Iraq resulted in a number of small defections to ISIS in the province, most notably in the border town of Abu Kamal. The effect of the ISIS Iraq campaign on the Syrian battlefront was alone insufficient to prompt a game-changing shift in the provincial balance of power in Deir ez-Zour. With the establishment of a “caliphate” on June 30 and the call for hijra [migration] into the Islamic State by ISIS leader and self-declared Caliph Ibrahim (ISIS leader Abu Bakr al-Bagdadi), however, ISIS shaping operations have yielded successive surrenders of local forces, who have pledged bay’ah to al-Baghdadi and surrendered their towns to ISIS. While the Mujahideen Shura Council and a number of prominent rebel religious committees immediately rejected the legitimacy of the caliphate, the declaration and events surrounding it have nonetheless significantly influenced the resolve of local and tribal rebel groups and has fundamentally altered the state of play in the province.
ISIS Advances in Deir ez-Zour Province Prior to the Declaration of the Caliphate
ISIS forces made a number of significant territorial gains in the weeks prior to the declaration of a caliphate. Beginning in mid-June, ISIS expanded its attack zone outside the focus of its April-May campaign in the Deir ez-Zour–al-Basira–as-Suwar triangle. While maintaining pressure on the heavily contested city of al-Basira, ISIS forces launched a concerted effort to seize towns along the Euphrates River south of Deir ez-Zour city and along the Khabur River south of as-Suwar. After meeting stiff MSC resistance in the village of Khosham, ISIS initially pursued a cease-fire with the MSC mediated by the local Abdullah ibn al-Zobayr batallion. However, the cease-fire quickly broke down and ISIS successfully ousted MSC forces from Khosham on June 9. In the neighboring town of Hatla, ISIS carried out night raids within the city and burned down houses of fighters from JN and allied rebel battalions prior to seizing the town. Such preparatory efforts have been used consistently by ISIS in order to create conditions of battle conducive to an ISIS attack, and are likely to continue in remaining battlefronts.
After securing its hold on these towns, ISIS launched attacks against the towns of Mohassan, al-Bu Amr and al-Bu Layl on the western bank of the Euphrates, seizing all three on June 19. In Mohassan, an ISIS-allied battalion with presence in the town kidnapped the deputy of the military council leader and two commanders from the local al-Haq brigade. Their bodies were later found on the banks of the al-Furat river as ISIS seized control of the town. ISIS also appears to have leveraged a prominent defection in its advance on Mohassan; former commander Abu Haroun was captured executed by the MSC after defecting to ISIS in the town. The seizure of these three towns has conferred onto ISIS a significant foothold on the road leading to the Deir ez-Zour military airport, and was met with a significant increase in regime airstrikes against ISIS locations throughout the province.
The next significant ISIS advance occurred farther south in the border town of Abu Kamal. On June 24 the local JN affiliate, the Jund al-Haq Brigade, switched sides to ISIS, prompting a flurry of confusion amongst rebel ranks in the area as ISIS moved into the town. An ISIS contingent under the command of former FSA commander Saddam al-Jamal is reported to have crossed into the Iraqi border town of al-Qai’m from the al-Kom area in the outskirts of Abu Kamal on June 25, and is the likely force to have entered Abu Kamal. As ISIS consolidated its foothold, the MSC began to reallocate its forces within the province in order to fortify its own key terrain. It withdrew forces from the banks of the Khabur River toward the al-Omar oil field and the MSC stronghold of as-Shahil, allowing ISIS to seize control of the villages of of Hariji and Tel-Duman on June 25. The MSC also sent a significant convoy of reinforcements to as-Shahil on June 28, posting a video claiming to show a 100-vehicle convoy transporting 1,000 fighters. On the same day, the MSC sent reinforcements to bolster rebel forces within Abu Kamal as ISIS continued to advance within the town. However, ISIS seized effective control over the town on July 2 after receiving reinforcements from al-Qa’im and the T-2 oil station near the Iraqi border, as it simultaneously seized the town of al-Zir to the north.
ISIS gains in Deir ez-Zour Province
Critical Defections Prompt a JN Withdrawal
The surrender of local and tribal rebel forces throughout Deir ez-Zour province following the declaration of the Islamic State is a critical inflection that has dramatically altered the scope of ISIS control within the province and has prompted a strategic withdrawal and recalculation by remaining MSC forces. Prominent rebel surrenders to ISIS occurred in the previous MSC strongholds in as-Shahil, al-Mayadin, al-Quriyah, and al-Ashara in addition to smaller villages including Dhiban, Swedan, al-Jazira, Sedan Shameyyi, and Darnej. While some of these groups stopped short of pledging full allegiance to the caliphate, their decision not to fight ISIS illustrates the influence of ISIS’s increased strength. In addition to the discord created by the caliphate, rebel forces were coerced into surrendering by consistent targeting by ISIS in recent weeks; As-Shahil has witnessed regular ISIS pressure through bombardment and clashes in the outskirts of the city. Al-Mayadin has been the target of a number of VBIEDs and unknown explosions amidst increased pressure from ISIS in the surrounding countryside. The nearby village of al-Quriyah was the target of a number of IEDs in the last two weeks in addition to an ISIS ambush that targeted a rebel battalion in the area on June 18.
Following these defections, JN forces withdrew from their positions in as-Shahil, al-Maydin, and the al-Omar oil field, allowing ISIS to enter these towns without a fight and granting it control of one of Syria’s largest oil fields. With these unprecedented developments, ISIS’s force posture in the province will dramatically shift as it moves in to consolidate control and establish command throughout its new territory. Capitalizing on its growing momentum, ISIS is likely to escalate against other attack zones northwest of Deir ez-Zour city in order to link up its zones of control and connect its Raqqa strongholds to its critical supply lines in Deir ez-Zour province. ISIS has maintained pressure on rebel groups by targeting both military headquarters and the homes of rebel commanders in the primary attack zones of al-Tarif and al-Shamitiya, and it is likely that these towns will be the next target of the ISIS offensive in the province.
Deir ez-Zour City
While Deir ez-Zour province has suffered significant upheaval, the city of Deir ez-Zour remains in a stalemate. The regime controls of three of the four entrances to the city and two neighborhoods within the northwest sector, in addition to its strongholds in the southern countryside at the Brigade 137 Base and the Deir ez-Zour military airport. Clashes between the MSC and regime forces within the city are ongoing, amidst continual regime bombardment of rebel-held neighborhoods. The final entrance to the city is under the control of ISIS, rendering the rebel elements within the city completely besieged. The combined pressure of the ISIS and regime blockades has placed a heavy burden on the population as well as the rebel fighters, and fears of starvation are high. In response to the growing humanitarian disaster, a truce was signed between ISIS and JN on June 18 in which ISIS agreed to deliver humanitarian aid into the city in return for a JN withdrawal from its al-Jesr checkpoint on the internal side of the al-Siyasa Bridge. ISIS delivered a second batch of provisions to the city on the first day of Ramadan on June 29, this time advertising it had also delivered ammunition to rebel brigades. No such deals have been made by the regime, and as a result ISIS remains the primary source of humanitarian supplies to the city.
ISIS’s position on the al-Siyasa bridge is ideal for maintaining its blockade on MSC fighters within the city, but is not a suitable staging area from which to launch a ground offensive into the city. However, since the fall of Mosul four top JN commanders within the city are reported to have defected to ISIS, and the JN military emir of the city was reportedly assassinated near the Siyasa Bridge on June 29. While unconfirmed, these reports come amidst increased tension between JN and rebel brigades within the city, and it is possible that the balance of power within the city is beginning to shift. If a number of rebel brigades within the city join with ISIS’s declared caliphate, the ability of ISIS to project force within the city is likely to increase and it is possible that an offensive to gain a foothold within the city will proceed.
Map of control within Deir ez-Zour city
ISIS’s recent gains on the western bank of the Euphrates river in Mohassan, al-Bu Amr, and al-Bu Layl have also opened up a key route from which ISIS can escalate against the regime-held Deir ez-Zour military airport. While rebel forces have made a number of attempts to seize the airport, ISIS has historically refrained from directly confronting the regime and has instead relied on the use of indirect fire to contain regime forces within a siege. This tactic has been used prominently in ar-Raqqa and neighboring Tabqa, where regime forces within military bases remain besieged but have not yet been faced with an ISIS attempt to storm the compound. However, if defections throughout Deir ez-Zour continue to occur, it is possible that ISIS’s unprecedented strength in the province will enable it to directly attack the regime. Further, the significant increase in regime airstrikes against ISIS positions throughout the province may have removed the primary incentive for ISIS to show restraint against regime forces.