In January, America’s long-time Kurdish-led partners in the fight against the Islamic State (ISIS) were defeated in a lightning offensive by Syria’s transitional government. After nine months of failed negotiations, the eruption of hostilities between the two sides was predictable. So too was the fact that the subjugation and integration of the Syrian Democratic Forces (SDF) into the Syrian state would catalyze a US military withdrawal from the country. That followed several months later, in mid-April, just weeks after US intelligence warned that ISIS was working to “rebuild its ranks” and “expand safe havens in Syria.”
While developments in Syria’s northeast earlier this year were undoubtedly dramatic, with a third of the country falling into government hands in the space of days, the process of integrating the SDF into the state has proceeded apace in the months since. Though complex, time-consuming, and fraught withchallenges, this effort has seen the establishment of four Kurdish brigades staffed by a total of 5,200 soldiers, all now officially part of the Syrian Ministry of Defense chain of command. Approximately 10,000 Kurdish local security forces — including at least 1,000 women — are set to be integrated into the Ministry of Interior. There is still a long way to go, but the signs so far have been encouraging.
Even more significant is the apparent collapse of ISIS in the wake of the SDF’s military defeat and subsequent integration, followed by the withdrawal of US troops. In fact, ISIS attacks declined by 17% in the months following the SDF’s losses (that is, from January to April 2026) and then plunged by a further 67% after the departure of American forces (from April through June 2026).* In all of May 2026, ISIS conducted just eight attacks across Syria, leaving four people dead — a far cry from the 2025 average of 29 attacks and 15 deaths per month and marking the lowest number of attacks and deaths since the group’s emergence in Syria in 2013.
The Fall of the SDF as a Key Enabling Factor
In the Syrian context, there has been a long-time assumption that any defeat of ISIS would depend heavily upon a sustained US presence and military lead. For many years, that calculation was justifiably linked to the fact that the former regime of Bashar al-Assad lacked the will and capacity to seriously tackle the jihadist group. Assad’s priorities lay in confronting Syria’s opposition communities in densely populated areas of the country, not in tackling ISIS’s presence in the vast central desert.
However, conditions fundamentally changed when the collapse of Assad’s regime in December 2024 opened up the rest of Syria to potential US military actions. In a tangible demonstration of this newfound freedom of maneuver, American jets launched more than 75 strikes on ISIS targets throughout what had been regime-controlled desert areas on December 8, just hours after Assad departed for exile in Russia.
While such strikes no doubt had an impact, the true catastrophic loss for ISIS was the end of Assad’s rule itself; the group had relied for years on the brutal persistence of his regime and all of its destabilizing knock-on effects to recruit members and justify its attacks. Compounding that shock to the system was the emergence of a new government in Damascus that was not just the victor in the conflict, but which sought explicitly to represent, empower, and seek justice for Syria’s Sunni majority — whose anger and desperation under Assad’s rule ISIS had long sought to prey upon.
The effect of this change in dynamics was dramatic. In 2025, ISIS’s operational tempo declined by nearly 50%, and the deadliness of its attacks dropped by 76%. In an attempt to adapt to its newly challenging circumstances, ISIS clearly viewed the Kurdish-led SDF and its control over northeast Syria — a region home to a sizable Kurdish population but an Arab majority overall — as its next best opportunity. In other words, Arab unhappiness under the SDF’s domineering rule created fertile ground for ISIS to exploit. Removing it hamstrung ISIS recruitment, freedom of action, and operations. Indeed, 90% of the group’s attacks in 2025 took place in SDF-held areas, where it sought to exploit and exacerbate growing anger within Arab tribes at their SDF rulers.
The SDF’s subsequent defeat in January 2026, paired with the resulting withdrawal of US military forces — whom many Arabs saw as the enabler of SDF rule — came as a second powerful shock to the system for ISIS, catalyzing a combined 72% decline in attacks, from which the group has been unable to recover so far. Crucially, ISIS has a track record of recovering from positions of adversity, and its ability to do so once again should be cause for concerted efforts by the Syrian authorities to neutralize what remains of the group across the country.
While these developments and their consequences may not be surprising, their significance should not be missed, particularly with regard to the drivers of violent extremist movements like ISIS. At a certain point, the presence of US forces and the role of their SDF partners had not only lost their value in the counter-ISIS fight, but had in fact become counterproductive.
This was revealed not by the events at the start of this year, but some time earlier. While the partnership between the SDF and US forces was no doubt instrumental in dealing a defeat to ISIS’s territorial state in early 2019, the challenge after that point shifted away from semi-conventional conflict and toward localized counterterrorism, law enforcement, and governance actions. These were tasks that the SDF was ill suited to pursue. It was, ultimately, a militia movement widely perceived to have prioritized the interests of one Kurdish political cause along with other political, social, and cultural causes that were anathema to other communities preyed upon by ISIS. The SDF’s partnership with the United States tarnished it further because many Syrian Sunni Arabs still had a bad taste in their mouths from American behavior toward Sunni Arabs in neighboring Iraq, especially before the 2007 surge. For these reasons, and although it took several years to become clear, after 2019 the US-SDF partnership could not prevent a gradual ISIS recovery. By 2024, ISIS attacks had tripled and deaths doubled compared to the year before.
Today, Syria’s transitional state has the responsibility of dealing with what remains of the jihadist group. As a member of the Global Coalition to Defeat ISIS, Syria is now incorporated into coalition bodies, with Syrian personnel permanently deployed within the effort’s command center in Amman, Jordan. As the lead entities on domestic counterterrorism, Syria’s Ministry of Interior and General Intelligence Directorate maintain close operational relationships with international partners, including the US, conducting joint operations and intelligence sharing, according to Ministry of Interior spokesman Nour al-Din Baba.
Growing Government Capabilities
Syria’s current interior minister, Anas Khattab, is no stranger to combating ISIS, having led a years-long counterterrorism campaign against it in Idlib between 2018 and 2024. In that context, as Khattab explained to the author, he relied upon a network of “infiltrators” who methodically inserted themselves into ISIS cells, feeding him intelligence and mapping out its broader structure and activities, allowing for bigger strategic blows against the group, rather than isolated tactical achievements. It was such methods that allowed Syrian forces to capture ISIS’s overall leader for Syrian operations, as well as its commanders for Damascus and southern Syria, in successive raids over two weeks in late December 2025 and early January 2026.
One of Khattab’s most prized assets within ISIS was Khaled al-Masoud, whose role as a double agent was revealed only when US forces fatally shot him in a raid in October 2025, before realizing who he was. Though he was hurried to a local hospital for treatment, he died in surgery, revealing a deadly shortcoming in the still-forming US-Syrian security relationship.
According to Syrian intelligence, what remains of ISIS’s presence in the country today “consists of scattered individuals united only by an ideological bond, but without any organizational structure that would enable them to pose a serious threat to the security of Syria or the region.” This is good news, of course, because this is what the slow death of a terrorist group often looks like. However, if the group can somehow hang on, it could also make the challenge that follows even harder because a dispersed cellular terrorist threat is far more difficult to fully eliminate.
To accomplish that goal, Syria’s security apparatus would need to remain squarely focused on the job at hand, and require significant international support. Despite the controversial history of many of those in power in Damascus, the Syrian government’s record in combating ISIS has been encouraging, resulting in the launch of dozens of raids and the foiling of 10 large-scale ISIS plots thanks to intelligence sharing, particularly with the US.
The Syrian government’s forcible integration of the SDF earlier this year drove something of a wedge between the US military and Damascus in 2025 — so much so that the Defense Department’s latest Inspector General report described the relationship as “in limbo.” But to the extent that the US prioritizes ISIS’s enduring defeat in Syria, it will have no choice but to work with new Syrian government. This appeared to be acknowledged by US Central Command commander Adm. Brad Cooper in his annual testimony to the Senate in May 2026, when he said the US would “pragmatically expand CT collaboration with the Syrian government” while “supporting efforts to responsibly build Syrian security capacity through regional partners.” While the SDF’s military integration into the Syrian state should help, the drivers behind ISIS’s recent collapse clearly underline that a relationship centered in Damascus is the best way to achieve it.
Crucially, this does not require and should not involve “boots on the ground” in the form of bases and large numbers of American personnel in Syria, but it should involve supporting Syria’s own domestic capacity. Through continued intelligence sharing, but also the provision of training, institutional capacity building, and infrastructure and technological assistance, the US and its allies can successfully accomplish what the Trump administration calls “burden-shifting” — placing the onus of responsibility on partner forces to take a lead in counterterrorism.
Charles Lister is a Senior Fellow at MEI.
*This data comes fromSyria Weekly, published by the author, which monitors and collects data on every violent incident across Syria, as reported and cross-verified by at least two vetted and reputable sources, including mainstream news outlets, social media, and direct official sources.
الصورة من تصوير رامي السعيد/NurPhoto عبر Getty Images
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