A series of ISIS defeats in Iraq and northern Syria over the past three months have driven ISIS to shift the focus of its Syrian campaign into central and western Syria in order to reestablish an image of military strength. ISIS was required to seek an alternate focus for its war effort in Syria due to its inability to defeat YPG forces in Aleppo and Hasaka Provinces. ISIS appears to have decided to target the Syrian regime rather than escalate directly against JN or Syrian rebel groups, and will likely continue capitalizing on disruptions in the regime’s military campaign in Idlib and Dera’a in order to maximize the effect of its own attacks in central Syria. ISIS may conduct a major attack against critical regime terrain such as the Palmyra Military Airbase or the regime and Hezbollah stronghold of Qusayr near the Lebanese border. If ISIS forces begin to display the ability to hold overrun regime positions in eastern Homs and Hama Provinces, this would be an indicator of a near-term ISIS offensive in the Syrian central corridor.
ISIS must balance its expanding activities in central and western Syria with the requirements of its ongoing defensive operations in northern and eastern Syria. ISIS escalation in central Syria may invite opportunistic or retributive counterattacks against ISIS forces in northern and eastern Syria by either YPG or Syrian regime forces. ISIS must maintain stable defensive lines in order to protect core ISIS interests in both Syria and Iraq. These include cross-border smuggling routes into Turkey, ground lines of communication connecting ISIS in Syria to ISIS in northern and western Iraq, and ultimately the de facto ISIS capital city of ar-Raqqa. ISIS appears to calculate that it is possible to maintain this defense by leveraging rebel defections to ISIS to offset the resource requirements of expansion into the central corridor. ISIS therefore prioritizes changing the calculus of rebel groups to favor ISIS expansion, and does so by disrupting the existing security environment. ISIS will likely also leverage its operations against the regime to curry favor with rebel groups, who may opt to facilitate increased ISIS activity in western Syria if directed against the Syrian regime. This expansion into western Syria will present a challenge to the anti-ISIS coalition, as it will likely to be unwilling to or unable to target ISIS positions inside core Syrian terrain.
1: ISIS Consolidates Defensive Posture Near Ayn al-Arab
ISIS consolidated its defensive lines in eastern Aleppo Province following its retreat from Ayn al-Arab/Kobani in January 2015, as joint YPG-rebel forces operating under the Euphrates Volcano Operations Room and supported by U.S.-led anti-ISIS coalition airstrikes pushed southwest to challenge ISIS terrain along the Euphrates River. ISIS destroyed the Shuyukh Fawqani and Qarah Qawqaz bridges in mid-March after withdrawing to the western bank of the Euphrates River, ceding control of several villages to YPG-led forces in order to leverage the Euphrates as a natural barrier to YPG expansion. The slowdown of the Kurdish advance outwards from Ayn al-Arab/Kobani likely reflects Kurdish inability to project force deeper into the southern Ayn al-Arab countryside in order to challenge ISIS-held terrain along the M4 highway. It is also likely that the YPG do not seek to attack deep into the ISIS-held interior, where there is a minimal Kurdish population. ISIS is therefore likely to maintain its now-fortified positions on the western bank of the Euphrates River, and is unlikely to be challenged in its southeastern Aleppo or Raqqa terrain in the near term.
2: ISIS Maintains Pressure on YPG Forces in Western Hasaka Province
ISIS has applied consistent offensive pressure against key YPG terrain along a frontline stretching from Ras al-Ayn on the Turkish border southeast through Tel Tamir and the Assyrian Christian villages of the Khabour Valley to Hasaka city. Taking advantage of the limited coalition air support provided to YPG forces in the province, ISIS launched an offensive
against Ras al-Ayn on March 10, seizing Tel Khanzir and several
other villages west and south of the town in clashes which included two separate
Vehicle-Borne Improvised Explosive Device (VBIED) attacks. Meanwhile, ISIS militants continue to combat
joint YPG-Assyrian forces in the western countryside of Tel Tamir following a late February ISIS offensive which seized most of the western bank of the Khabour River. Since March 20, ISIS also conducted three Suicide VBIED
(SVBIED) and VBIED
attacks against Kurdish neighborhoods of Hasaka city in an apparent attempt to weaken the resolve of Kurdish populations to continue their campaign against ISIS. Although ISIS has not managed to make major gains in these offensives, the constant pressure applied to western Hasaka Province is likely sufficient to prevent further YPG advances that could challenge ISIS-held terrain along the Turkish border west of Ras al-Ayn.
3: ISIS Enhances Security Measures in Eastern Deir ez-Zour
ISIS has intensified internal security measures in eastern Deir ez-Zour Province in response to frequent attacks
by unidentified militants against ISIS security patrols and checkpoints in the town of al-Mayadin in addition to persistent rumors
of the establishment of anti-ISIS rebel sleeper cells in the region. ISIS continued its ongoing mass arrest campaign
targeting former members of Jabhat al-Nusra and other rebel brigades. This campaign likely allows ISIS to address internal security fears through intimidation, to neutralize cells of potential resistance, and possibly to replenish depleted ISIS manpower reserves through conscription. Meanwhile, reports from March 27-28 indicated that ISIS fighters are reinforc
of interlocking trenches and berms around important ISIS urban terrain, suggesting that ISIS also fears an external challenge to its control over the Euphrates River Valley. ISIS first implemented
this type of reinforcement in early January, digging a trench southwest of Abu Kamal, and has since expanded this fortification to almost fully encircle the border town in addition to constructing similar defenses surrounding al-Mayadin. ISIS likely perceives a continued threat from Deir ez-Zour tribes based in the eastern countryside of the province, who have previously resisted ISIS consolidation of power over the area. These fears may have been stoked in part by a regime raid
against the ISIS-held T2 oil field west of Abu Kamal on March 4, which marked the first hostile incursion into eastern Deir ez-Zour Province since ISIS seized the area last year.
4: ISIS Assaults the Syrian Regime in Central Syria
ISIS appears to have designated a new main effort against the Assad regime in central Syria beginning in early March 2015. Over the past month, ISIS forces launched a series of successful hit-and-run attacks against regime checkpoints
, military facilities
, and oilinstallations
throughout eastern Homs and Hama Provinces including recent assaults against an air defense battalion
near the Tiyas (T4) Airbase east of Homs City on March 27 and the regime-held village of Mabouja
east of Hama City on March 31. The nature of these offensives suggests that ISIS seeks to shape the conditions for future territorial gains in central and western Syria while bolstering ISIS morale with a new narrative of victory. ISIS has conducted executions of alleged regime collaborators, massacres
of Alawite civilians, and publicized beheadings
of regime fighters in an effort to establish a perception of dominance over the Syrian regime and likely to maximize the asymmetric effect of ISIS attacks through psychological warfare. Increasing the visibility of this campaign, ISIS reestablished its “Wilayat” [Province] in Hama Province on March 29, releasing a video
branded with the Wilayat Hama logo after over a year
of silence. The reestablishment of the ISIS Hama media office underscores the propaganda value that ISIS seeks to derive from its operations against the regime in this region, and may signal ISIS intent to formalize its governance activities in the area. However, ISIS forces in Homs and Hama Provinces do not appear able to conduct sustained operations or hold recently-seized terrain. Multiple reports
of ISIS withdrawals
following heavy regime aerial bombardment suggest that ISIS units in central Syria may not currently possess sufficient resources to decisively overcome the Assad regime’s military advantages. Nonetheless, by threatening key regime terrain such as the Palmyra Military Airbase
, the supply routes to Aleppo
and Deir ez-Zour
cities, and the natural gas infrastructure
which provides much of Syria’s electricity, ISIS may achieve asymmetric effects against the regime. This could include forcing the regime to redeploy additional reinforcements to the region, creating opportunities for ISIS expansion into the Syrian central corridor.
5: ISIS Builds Presence in the Damascus Countryside
ISIS cells in western Syria continue to infiltrate and subvert opposition-held terrain. ISIS persists in its effort to expand into rebel-held areas of Qalamoun
and the southern and eastern countryside of Damascus
, increasingly challenging rebel control of terrain and the unity of rebel ranks. This is likely in order to secure lines of communication that connect ISIS forces in the eastern Homs countryside to ISIS forces positioned along the Lebanese border and inside Damascus city. ISIS militants operating out of the Hajar al-Aswad neighborhood of southern Damascus are accused of conducting an escalating campaign
of prominent opposition figures in the southern and eastern suburbs of the city in early March. This campaign is targeted to generate local disorder and rebel disunity that can create exploitable opportunities for ISIS expansion. ISIS has also worked to strengthen its direct governance in southern Damascus through public executions, including the March 20 beheadings
of three men accused of colluding with the regime. However, ISIS expansion into Damascus Province is met with active hostility
from JN, Jaysh al-Islam, and other opposition factions which will be difficult to overcome without additional investment of resources or manpower by ISIS in the near term.
6: ISIS Tests Rebel Unity in Aleppo
A stagnated front line persists between ISIS and rebel forces supported by JN north of Aleppo city. ISIS appears engaged in an effort to disrupt security in rebel and Kurdish-held areas of western Aleppo in order to create an opportunity for ISIS to advance. The objective of the stalled ISIS military offensive north of Aleppo city appears to be to seize control of the rebel supply line passing from the Bab al-Salama border crossing into the former ISIS stronghold of Azaz. Throughout March, ISIS demonstrated the ability to penetrate into Kurdish and rebel-held terrain through sleeper cell activity. Both the YPG and Ahrar al-Sham claimed to have arrested
ISIS sleeper cells
. An SVEST attack
on March 25 targeting a rebel checkpoint west of Aleppo city appeared to further validate fears of ISIS infiltration into rebel terrain. ISIS complements these efforts through a propaganda campaign that attempts to justify ISIS aggression toward certain rebel groups under the guise of combating Western influence and secularism. ISIS has also increased its defensive fortifications north of Aleppo city, possibly in response to a recent increase in JN and rebel tactical victories against the regime in the area. ISIS forces are reportedly digging
a network of trenches near Dabiq, building concrete rooms to protect ISIS forces from anti-ISIS coalition airstrikes, and ordering the evacuation
of civilians, likely to enable increased fortification in the area. ISIS is likely to continue these two lines of effort in Aleppo in the near term rather than launching a direct offensive against JN and rebel forces.