By Emily Anagnostos and the ISW Iraq Team
The Iraqi Security Forces (ISF) moved deeper into Mosul’s eastern neighborhoods as the ISF and Peshmerga made significant gains on Mosul’s eastern and southern axes in an effort to encircle the city.
The Counter Terrorism Service (CTS) and 9th Iraqi Army (IA) Division advanced deeper into Mosul’s eastern neighborhoods, entering and encircling several neighborhoods from November 4 to 7. The pace of the ISF’s operations in eastern Mosul remains faster than expected, but the ISF still faces resistance from ISIS, which has deployed rooftop snipers, suicide attackers, and heavy artillery in order to slow the ISF’s advance. These tactics, as well as ISIS’s mining of homes and roads with IEDs, likely aim to slow down the ISF’s advance in order to buy ISIS time to fortify their defenses in the city center. Lingering ISIS attacks in eastern Mosul will also require forces to remain in the area. The CTS and Iraqi Army will therefore need to have a hold force in place to secure recaptured neighborhoods and fleeing civilians before they can advance further into Mosul’s center.
The ISF and Peshmerga advanced the objective to encircle the city, retaking major towns on Mosul’s northeastern and southern axes. The Peshmerga retook the ISIS-held town of Bashiqa, northeast of Mosul, on November 7, after besieging the city since October 23. ISIS attempted to repel the advance using chlorine and mustard gas, underscoring ISIS’s continued commitment to using chemical weapons during the counter-offensive. Bashiqa’s recapture frees up CTS forces to support ongoing operations in Mosul itself or bolster the 16th IA Division’s line of effort north of the city. Meanwhile, the Federal Police and 15th IA Division recaptured Hammam al-Alil, the last major ISIS-held town on Mosul’s southern axis, on November 5. The Federal Police continued its advance north, coming within five kilometers of the airport located in Mosul’s southern city limits on November 7. The airport could prove valuable terrain for the ISF and the Coalition as a staging ground for further operations to recapture the city center.
ISIS countered these gains by striking behind the front lines, demonstrating resurgent attack capabilities in recaptured territory. ISIS launched a major attack in Shirqat on November 4, infiltrating the town from ISIS-held terrain on the eastern bank of the Tigris River before security forces repelled the attack. ISIS also carried out twin suicide attacks in Tikrit and Samarra on November 6, striking far behind the Mosul frontline to target Shi’a pilgrimage routes in the lead up to Arbaeen, a major Shi’a holiday. The suicide attacks were accompanied by the detonation of two stationary IEDs near Tikrit, demonstrating that ISIS has re-established an attack presence in or near the city. These attacks foreshadow ISIS’s coming shift into a traditional-style insurgent group in the face of its loss of control over terrain. ISIS may try to increase spectacular attacks in areas like Samarra and Tikrit, where it can demonstrate its capacity to infiltrate highly-secure areas, and may try to infiltrate inner Baghdad neighborhoods next. ISIS may also refocus its efforts on re-establishing attack and support zones in recaptured parts of the country.
ISIS’s calculus for Mosul’s defense may also change now that the U.S.-backed Syrian Democratic Forces (SDF) opened efforts to isolate ISIS-held Raqqa in Syria on November 6. ISIS may elect to shift assets from Mosul, which it likely assess it will lose, to Raqqa, which it likely calculates it stands a better chance of retaining by exploiting Kurdish-Turkish seams in the anti-ISIS alliance. ISIS may also calculate that it is better able to regroup in the desert in Deir ez Zour, where it can still maintain a connection with the ISIS-held town of al-Qa’im in western Iraq, more so than in Ninewa, where the Coalition is less susceptible to such seams. The U.S. will thus need to both ensure that the ISF continues anti-ISIS operations beyond Mosul, particularly in the upper Euphrates River Valley, and sufficiently bolster the Syrian operations to prevent ISIS from retaining safe havens in the region which could allow it to reconstitute even after losing its capital cities.