In March 2024, the Islamic State killed more people in parts of Syria controlled by the Assad regime than at any point since July 2018. The attacks are part of an ongoing trend since October 2023 that has seen Islamic State activity in this area grow to levels unseen since the group lost control of its territorial caliphate.
This growth is largely attributable to the recent withdrawal of thousands of Russian and Iranian troops from parts of Syria controlled by the Assad regime, which has given the Islamic State more space to operate than at any point since 2017. The prospect of a new war between Israel and Hizballah in Lebanon threatens to exacerbate this trend, as Iran would likely redeploy thousands more of its proxy forces from Syria, Iraq, and elsewhere to reinforce Hizballah positions should a war occur.
The United States should take note of these developments and ramp up its number of raids and operations against the Islamic State, which have declined 16 percent compared to 2023. This was largely due to reduced U.S. troop activity after Oct. 7, 2023, when Iranian-backed groups carried out more than 170 attacks against American personnel.
The United States should also immediately resume training courses for Syrian Democratic Forces’ prison guards, which have been put indefinitely on pause in 2024. The issue of prisons is particularly urgent. The Syrian Democratic Forces are currently holding more than 50,000 veteran Islamic State members and their relatives at 27 detention centers across northeast Syria, many of which have already been the target of prison break attempts by Islamic State cells.
Rising Risks
The growth in Islamic State activity has been sufficient to elicit a rare statement of warning from U.S. Central Command, which recently claimed that, “From January to June 2024, ISIS has claimed 153 attacks in Iraq and Syria. At this rate, ISIS is on pace to more than double the total number of attacks they claimed in 2023.”
In truth, Central Command’s assessment of the Islamic State’s growth represents a serious understatement, as it only accounts for attacks that the group itself has claimed responsibility for. As has been widely documented, since 2020 the Islamic State has deliberately under-reported its attacks in Syria — claiming on average 25 percent of the total — as part of a strategy to re-establish itself without attracting the attention of its adversaries. More accurate data from a collection of experts puts the total number of Islamic State attacks in Syria alone in the first half of 2024 at 551, with the vast majority occurring in areas controlled by the regime of President Bashar al Assad.
The Assad regime has struggled to contain the group’s resurgence as the wars in Ukraine and Gaza have produced downstream effects that have forced both Russia and Iran to withdraw thousands of personnel from key parts of the country where the Islamic State operates. Following the Wagner Group’s June 2023 mutiny in Rostov-on-Don and Israel’s expanded bombing campaign of Iranian targets in Syria in early 2024, thousands of Russian and then Iranian forces withdrew from the country. In both cases, the Islamic State was able within weeks to take advantage of the vacuum and carry out record breaking levels of violence. Now, the fallout from the Gaza conflict threatens to provoke a new war in Lebanon between Israel and Hizballah that would likely produce a third wave of withdrawals, in particular of Iranian-backed Iraqi, Afghan, and other militiamen who have pledged to deploy to Lebanon should a war occur.
Since 2012, these foreign militia have formed the backbone of Iranian-backed infantry units in Syria’s Central Desert — the Islamic State’s main area of operations — and other sensitive frontline positions in Aleppo, Damascus, and southern Syria. If they withdrew, it would be disastrous for the region and grant the Islamic State even greater freedom of movement to conduct attacks. This includes in areas of northeast Syria controlled by the United States and its partners, the Kurdish-led Syrian Democratic Forces, which in 2024 also saw a 320 percent increase in Islamic State attacks compared to 2023.
According to the U.S.-led coalition’s most recent quarterly report, by March 2024 Islamic State attacks against the Syrian Democratic Forces were double that of any other month going back to January 2022. Local reports claim the number of attacks in April 2024 was even higher. In May and June 2024, the Islamic State carried out three suicide bombing attacks for the first time in years.
On June 5, 2024, the Assad regime attempted to address the threat on its side by launching its largest anti-Islamic State campaign since 2021. However, unlike previous campaigns that were led mostly by Russian officers and Wagner mercenaries, this campaign is being led by three Syrian army units with close ties to Assad’s inner circle. These are the units traditionally responsible for recapturing and holding territory from moderate rebels in southern and northwest Syria.
By removing these units from other front lines, the Assad regime has left itself exposed, and in southern Syria violence has exploded since their withdrawal. That said, in the first month of the campaign, the Islamic State killed an estimated 69 pro-Assad fighters and wounded dozens more. The fate of many more who have fallen prey to the group’s ambushes in the desert remain unknown. As of now, the campaign’s overall effectiveness remains unclear.
Exploited Opportunities
Since losing the last of its territorial possessions in Syria in March 2019, the Islamic State has waged a hard-fought campaign to ensure its survival, passing through several cycles of growth and collapse in the last 5 years. In each instance, the group’s expansion was driven by bouts of infighting amongst its adversaries that led to the withdrawal of foreign troops from key parts of the country, creating gaps the group exploited to carry out attacks and extort merchants and local communities.
The first of these gaps opened up during Turkey’s October 2019 assault on the Syrian Democratic Forces. Hundreds of U.S. personnel withdrew from the outskirts of key cities in the area, leaving Russian and Assad regime troops to take their place — although these cities remain jointly administered by the Syrian Democratic Forces, Russia, and pro-Assad troops. Many of these cities — such as Ain Aissa, Raqqa, Tabqa, and others — are located along the 712, 6, and 4 highways that link the Turkish city of Akçakale to Syria’s Central Desert, a sparsely populated 80,000 square-kilometer expanse nominally under the control of the Assad regime.
The Central Desert is home to a series of rugged, impenetrable mountains and a majority of Syria’s gas and phosphate reserves along with their processing infrastructure. This region separates Syria’s densely populated western strip from areas northeast of the Euphrates River controlled by the Syrian Democratic Forces. Following the loss of its caliphate, the area became a rear base and training hub for Islamic State cells who could take refuge in the mountains and launch violent ambushes at night on passing convoys of soldiers escorting energy shipments across the country.
After October 2019, the number of Islamic State fighters in the Central Desert grew, as Russian and Assad regime troops that controlled the 712, 6, and 4 highways had far fewer resources to patrol the area than U.S. forces. The group subsequently converted the highways into active smuggling corridors for foreign and local fighters entering the Central Desert from northeast Syria, at times coordinating with Russian and Assad regime troops who looked the other way in exchange for bribes.
By April 2020, Islamic State attacks in the Central Desert began to surge, a trend that continued, then doubled in August and remained constant throughout the rest of 2020. Despite this growth, a perfect mix of converging factors prevented Russia and the Assad regime from taking the steps necessary to rein in the group’s expansion.
First, the economic impact of the COVID-19 pandemic weakened the Assad regime’s already low capacity to patrol wide swaths of the country. In February and March 2020, significant fighting between the regime and armed opposition groups in northwestern and southern Syria further diverted the former’s focus and its ability to redirect troops elsewhere.
Across the Mediterranean, fighting in the first half of 2020 between Russian- and Turkish-backed factions in Libya further drew Moscow’s attention away from Syria. Rather than deploy fighters to the Central Desert, Moscow instead recruited thousands of Syrian mercenaries in early 2020 who were flown to Libya to fight alongside Russia’s ally and proxy, Gen. Khalifa Haftar.
Lastly, the Islamic State was helped by local developments in the Central Desert itself. In June 2020, an intense rivalry emerged between the Assad regime’s two most powerful commanders in Deir Ezzor province, whose units in turn clashed with one another and refused to cooperate in carrying out patrols. In addition to granting the Islamic State greater freedom of movement, both commanders allegedly cooperated with the group against one another, providing it intelligence on the other’s movements that facilitated several large massacres. One such massacre of 39 troops on New Year’s Eve 2020 finally pushed Russia, Iran, and the Assad regime to form a joint operations room, which from January to March 2021 killed off much of the Islamic State’s active leadership and fighting ranks in the Central Desert.
It would not be until fall 2023 that a similar mix of circumstances emerged to create gaps that the Islamic State could exploit to resume attacks against Assad regime troops at the same level that it did in 2020. Once again, these circumstances were driven by infighting within and between regional states that preceded the withdrawal of foreign troops, in this case those of Russia and Iran.
The first instance occurred after the Wagner Group’s failed June 24, 2023 mutiny against Russian army units in Rostov-on-Don. In early September 2023, shortly after the death of Wagner commander Yevgeny Prigozhin, thousands of the group’s fighters withdrew from Syria after refusing an ultimatum to merge either with units affiliated with Russia’s Ministry of Defense or Redut, a smaller Russian mercenary outfit and long-time rival of Prigozhin. Despite the apparent blow to a core pillar of his regime, Assad welcomed the withdrawal, and similarly refused offers from Redut to dispatch forces to replace Wagner fighters in the Central Desert — where the latter had disproportionately been deployed. This created a vacuum that the Islamic State could exploit.
In this case, tensions arose from disagreements over energy reserves. Wagner forces in Syria first deployed en masse to the Central Desert in July 2017, when a Prigozhin front company received a five-year contract from the state-owned Syrian Petroleum Company. According to this agreement, Wagner would receive 25 percent of all profits from oil, gas, and phosphate reserves that it captured from the Islamic State, which controlled the area at the time. Many of these facilities were built, owned, or operated in the 2000s by Stroytransgaz, a Russian company owned by Gennady Timchenko, a close Putin associate responsible for managing the Russian leader’s financial interests abroad. Throughout 2017, Stroytransgaz itself signed a new wave of contracts with the Assad regime securing rights to oversee production, transportation, and repairs at these and other sites.
At the time, the Assad regime was dependent on Russia and Iran to defeat the Islamic State and moderate rebel groups that still controlled wide swaths of the country, and so granted wide-ranging concessions to companies from both countries. However these deals generated widespread anger amongst Syria’s elite, who resented being excluded from the country’s most lucrative revenue generating sectors.
As large-scale fighting against moderate rebels drew to a close in 2020, Assad and his inner circle began to gradually seek ways to extricate themselves from both Russian and Iranian control. This goal was partially achieved by the Arab League’s May 2023 decision to readmit Assad, which Damascus hopes can serve as a stepping-stone towards rapprochement with western states. Wagner’s withdrawal along with Moscow’s shuttering of Prigozhin’s economic empire in summer 2023 therefore presented a rare opportunity for the Assad regime. It quickly sought to shake off one key pillar of Russian control and renegotiate the now-expired July 2017 deal on better terms.
The results on the ground were immediately apparent. Within weeks of Wagner’s withdrawal, the Islamic State launched a multi-pronged assault against remaining pro-Assad forces in the Central Desert, seizing the large Doubayat gas field near the border with Iraq on Oct. 18, 2023. Recapturing the gas field afterwards required more than a month of intense fighting by Iranian-backed Afghan Shia militias supported by significant Russian airpower.
During the battle, the Islamic State displayed tactical prowess against its more numerous foes. It deployed cells behind enemy lines to besiege small villages and ambush and massacre dozens of pro-Assad fighters on opposite ends of the desert to relieve pressure on Doubayat. By the end of the fighting, nearly 70 Afghan and Syrian fighters had been killed and dozens more injured.
Since then, Islamic State attacks have grown. In the first five months of 2024, the group’s attacks in Assad regime-controlled areas grew 213 percent compared to 2023, which itself saw a 68 percent increase compared to 2022. During 2024, nearly half of all Assad regime casualties occurred as a result of Islamic State attacks. The group’s momentum was again aided when Islamic Revolutionary Guards Corps commanders began to evacuate positions across Syria in early 2024 as Israel and the United States expanded their aerial assassination campaign against the group and its proxies. Though the largest number of withdrawals occurred in southern Syria, Iran has also evacuated three Central Desert bases in southern Raqqa province near the 712, 6, and 4 highways while reducing its footprint in others.
The significant uptick in attacks has also pushed Iran to investigate and arrest a significant number of its own proxy forces suspected of providing information to either Israel or the Islamic State, thereby driving partial demobilizations. Recently, the Islamic Revolutionary Guard Corps commander for eastern Syria along with Hizballah’s 313 unit — which recruits Syrians into Hizballah — established a new task force charged with performing full background checks on more than 1,500 veteran fighters across all Iranian-backed militias in the eastern province of Deir Ezzor. After completing these checks, the task force intends to conduct a second round of vetting of an equal number of new recruits. So far, the corps has arrested more than 80 of its own proxy fighters in 2024 suspected of collaborating with either Israel or the Islamic State.
Supporting the Syrian Democratic Forces
Unfortunately, the Syrian Democratic Forces have few innovative options available to deal with the growing threat. Following a spike in Islamic State violence in April 2024, they issued new residency directives requiring Arab refugees originally from areas outside northeast Syria to acquire newly created expatriate cards or be expelled. Almost immediately, more than 40 families living in Hasakah province were reportedly deported to Assad regime territory, while tens of thousands more qualify for a similar fate. Local activists suggested the arrests targeted communities that the Syrian Democratic Forces allege have ties to the Islamic State, though this cannot be confirmed.
Though Islamic State activity in Hasakah thereafter subsided, the group’s activity remains elevated in Deir Ezzor. There, fighters have increasingly begun to carry out numerous brazen robberies and seizures of oil tankers as part of a campaign to extort local businessmen.
U.S. forces in Syria should therefore brace for a period of growing instability in the medium to long term, particularly in the event that a conflict breaks out between Israel and Hizballah in Lebanon.
First, U.S. forces in Syria should ramp up anti-Islamic State raids and operations after a period of lull. According to Central Command’s semi-annual review, U.S. forces carried out 59 anti-Islamic State operations in Syria in 2024, killing 14 Islamic State members and arresting 92. This represents a 16 percent decline in operations and 72 percent decline in the number of Islamic State members killed or captured compared to 2023. This decrease can largely be attributed to a reduction in U.S. troop activity in Syria after Oct. 7, 2023, when Iranian-backed groups carried out more than 170 attacks against American personnel up until February 2024.
The United States should also attach increased urgency to resuming training courses for Syrian Democrat Forces’ prison guards, which have been put on indefinite hold in 2024. The Syrian Democratic Forces attribute the delay to a “lack of availability” as their leaders have had to contend with an increase in Turkish airstrikes targeting commanders and persistent tensions with some Arab tribes following an uprising in September 2023 that killed 150 people. The issue of prisons in northeast Syria is particularly sensitive as 54,600 Islamic State members and their relatives are being held in 27 detention centers run by the Syrian Democratic Forces across northeast Syria. These facilities have regularly been the target of prison breaks, including the al-Sinaa prison, which Islamic State cells briefly captured from Jan. 20 to Feb. 3, 2022, when they managed to release several dozen high-ranking leaders.
Despite this, U.S. forces continue to note a “general lack of professionalism within the detention facility guard force,” which only shares information “when it benefits them,” describing both sides’ overall relationship as “very transactional.” The Islamic State certainly harbors ambitions to launch more prison breaks in the future and, should security in the area deteriorate, it may successfully do so once again.
Though the current political climate in the United States likely will not permit it, in the medium to long term Washington should increase its troop presence in northeast Syria to expand its patrols along key highways where the Islamic State moves weapons and fighters between different regions. Since the Jan. 28, 2024 attack on U.S troops in Jordan, the United States increased its deployment of troops to the country by 20 percent, with the number growing from 3,000 to 3,813. A similar increase to the 900 U.S. personnel currently operating in Syria would have a significant impact in stabilizing an arguably more volatile and dangerous area.
Jeremy Hodge is a senior fellow at New America and research fellow at Arizona State University’s Future Security Initiative. Follow him on X @JeremyHodge2
Image: Sgt. 1st Class Nicholas J. De La Pena
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