Salafi-Jihadi Movement Update Special Edition: Iran, Russia, and Syrian Prioritization of Challenging the United States over ISIS Will Present ISIS with Space to Grow Its Capabilities, Rest, and Refit

This is a special edition of the Critical Threats Project’s (CTP) Salafi-Jihadi Movement Update. These special editions provide in-depth analysis covering one CTP portfolio. CTP's Salafi-Jihadi Movement Team covers the Salafi-jihadi movement in Afghanistan, the Horn of Africa, Iraq, North Africa, Pakistan, Syria, West Africa, and Yemen in our full Salafi-Jihadi Movement Weekly Update, which you can find here.

Iran, Russian proxies, and the Syrian regime have deployed forces along the line of control between Syrian regime forces and the US-backed Syrian Democratic Forces, likely as part of a coercive campaign to expel the United States from Syria.[i] Iran and the Syrian regime have surged forces and matériel to eastern Syria since July 7 under the auspices of defending against a US-Syrian Democratic Forces (SDF) offensive into regime-controlled territory.[ii] Iran and Iranian-backed militias have framed the US-led international coalition in Syria as an imminent security threat to local Syrians since late June.[iii] The surge has occurred alongside an increase in Russian coordination with Iran on planning and intelligence sharing in Syria.[iv]

Iran, Russia, and the Syrian regime are giving lower priority to counter-ISIS operations, which very likely presents ISIS with the space to grow its capabilities and rest and refit. The Russian Air Force continues to conduct some air strikes targeting ISIS, but the increase in flights aimed at harassing US forces in Syria since March draws Russian resources from counter-ISIS operations.[v] Russia maintains a mixed air regiment in Syria, but the war in Ukraine has imposed some constraints on assets, such as the withdrawal of a squadron of attack aircraft in March 2022.[vi] Iranian deployments along the line of control (LoC) also pulls resources from countering ISIS in the regime-controlled Deir ez Zor urban belt. ISIS has stepped up attacks and coercive efforts in the Deir ez Zor urban belt since early 2023, including intimidating locals by establishing shadow governance at night and hanging ISIS flags in Musayrib, north of Deir ez Zor city.

Russia replaced Wagner commanders in Syria posts with Russian Ministry of Defense (MoD) officers on July 8, which may temporarily degrade Russia’s ability to conduct counter-ISIS operations.[vii] Wagner defended Al Kawm against a major ISIS offensive in April, and it has repeatedly organized counter-ISIS operations in the central Syrian desert in 2023.[viii] Wagner commanders in central Syria benefited from sustained Wagner deployments to central Syria and coordinating operations against ISIS. The new Russian MoD commanders will not have the same knowledge, and therefore they will be more prone to poorer or slower decision-making. The Wall Street Journal reported Iran is attempting to recruit the Wagner-funded “ISIS Hunters,” a Syrian mercenary group whose members are no longer being paid by Wagner and returned to their homes in Palmyra, Syria.[ix] The decrease in the available manpower of pro-regime forces suggests negative impacts for counter-ISIS operations.

ISIS may be lying low in Deir ez Zor amid the buildup of Iranian, Syrian regime, and Russian-backed forces along the LoC. ISIS claimed only four attacks in Deir ez Zor since July 5, including when ISIS fighters killed an SDF fighter in Izba after ISIS supporters chanted in support of the organization there on July 4.[x] ISIS is still conducting other attacks, but it is not claiming them.[xi] It is also conducting isolated operations to maintain support zones north of the Euphrates River Valley, where ISIS fighters threatened 39 SDF members with death in the Khabour River Valley on July 17.[xii]

Figure 1. ISIS Activity in Northeastern Syria Since July 5

Source: Brian Carter and the Institute for the Study of War.

CTP is considering several scenarios in northeastern Syria that may affect ISIS’s ability to reconstitute itself in eastern Syria. The group’s efforts are currently contained by the US presence, though ISIS is setting conditions for a rapid resurgence after the US withdrawal. A change in US presence or activities under these scenarios would accelerate ISIS’s condition setting. The scenarios are not mutually exclusive. Iran, Russia, and Syria have the option to pursue more than one at a time or multiple scenarios sequentially. These scenarios are:

• Iran, Russia, and the Syrian regime retain their forces in eastern Syria but deprioritize expelling the United States from Syria. This would return the situation in Syria to a state in which Iranian and regime-backed forces intermittently clash with the SDF short of an offensive campaign into SDF-controlled territory. This scenario would also entail a low level of Russian harassment against US forces and an effective Russian MoD chain of command for counter-ISIS forces that is capable of making effective and quick decisions.[xiii] ISIS would restart its attacks on regime forces and the SDF as well as operations to create new support zones and co-opt locals. These efforts are currently experiencing success, and a decrease in the current tensions will contain but not defeat ISIS efforts.[xiv] The longer the SDF, regime, Iran, and Russia maintain forces along the LoC to pressure the United States and SDF before deprioritizing expelling the United States from Syria, the more ISIS will be able to build its support zones in other areas, such as near Raqqa or the Khabour River.[xv]
• Russia and Iran continue coordinated coercive pressure aimed at forcing a US withdrawal from Syria and deprioritize counter-ISIS operations. The SDF would respond by maintaining its forces along the LoC, which would limit ISIS’s ability to conduct operations in the east bank of the Euphrates near Deir ez Zor city. Russia and Iran do not conduct counter-ISIS operations to sufficiently degrade ISIS capabilities in regime-held Syria under this scenario. Limited Russian air support for counter-ISIS forces in central Syria would inhibit counter-ISIS operations. This would enable ISIS to more effectively fight pitched battles against pro-regime forces to deny regime access to key sanctuaries or seize regime supplies in central Syria.[xvi] It also may enable ISIS to strengthen its presence on both banks of the Euphrates.
• Iran directs or authorizes its proxies in Syria to use explosively formed penetrators against US forces or the SDF in northeastern Syria. The use of explosively formed penetrators (EFP) would deny the SDF access to certain areas, such as Baqqara tribal territory north of Deir ez Zor city, that Iran and the regime have previously targeted for recruitment efforts. ISIS already uses improvised explosive devices, which can generate similar tactical-level effects to EFPs, to deny SDF access to ISIS support zones.[xvii] ISIS would be able to take advantage of the denial effects of EFPs, even if it does not detonate them, because Iranian-backed sleeper cells responsible for the EFPs would not be prepared to control or secure the population. Iranian-backed sleeper cells are already present in northeastern Syria.[xviii]
• In a low probability but dangerous scenario, Iranian- and regime-backed forces attack SDF territory. An assault against the SDF-held areas in Syria would sap SDF bandwidth while pulling pro-regime forces from the west bank of the Euphrates. This would enable ISIS to build support zones in Deir ez Zor, where the population would not be secured by regime or SDF forces due to active combat between the regime and SDF. The high-intensity combat in this scenario and proximity of US forces to the fighting would risk inadvertent or intentional escalation between Iran, Russia, and the United States in Syria. New ISIS support zones caused by an inability for either the regime or the SDF to disrupt the group would allow ISIS to reconstitute key capabilities, such as planning cells and vehicle-borne improvised explosive device manufacturers, to target critical infrastructure. ISIS could use these assets to generate forces by targeting prison facilities.