Caught in the Crossfire: Islamic State Detention Sites at Risk

Almost overnight, the map of Syria has changed again as stalled talks between the central government and forces controlling the northeast escalated into violence. Misinformation and disinformation have spread rapidly, with each side blaming the other for releasing hundreds if not thousands of individuals affiliated with the Islamic State (IS) and held in local detention sites run by the Syrian Democratic Forces (SDF). As the situation continues to shift, questions are flooding in about the actual status of these sites, the future of the long-delayed detainee repatriation effort, and the important role that the United States has played—and should keep playing—on both issues.

The Past and Present of IS Detention Sites 

Between late 2018 and early 2019, as the SDF seized former IS territory with support from the U.S.-led coalition, thousands of men, women, and children affiliated with the terrorist group were captured and transferred to various pop-up detention sites in northeast Syria. With more than 70,000 Syrians, Iraqis, and third-country nationals (TCNs) taken into custody during this time, the SDF developed a policy to divide these populations: most women and children were separated from men, while many teenage boys (some as young as fourteen) were grouped with the men if they were perceived as IS fighters. Around 10,000 men and teenage boys were then sent to detention facilities, while most women and children were sent to closed detention camps. 

Over the years, some states have repatriated their detained citizens who traveled to join IS, while others have been reluctant to do so for political or security reasons. Even states that are willing to repatriate have largely focused on women and children; only a few (e.g., the United States and Iraq) have repatriated men. 

Today, around 35,000 detainees remain in roughly twenty-seven sites in northeast Syria, run by different actors such as the SDF, its affiliated forces, and its civilian wing, the Democratic Autonomous Administration of North and East Syria (DAANES). These sites can be roughly divided into two categories:

Detention facilities. As of late 2024—the last time any comprehensive information was publicly released on these locations—approximately 9,000 mostly male detainees were being held at twenty-five detention facilities: fifteen of them run by the SDF and its affiliated security forces—such as the Women’s Protection Units (YPJ) and Internal Security Forces (ISF)—and ten run by DAANES, including two youth “rehabilitation” centers at Houri and Orkesh. Most of those held in detention facilities are adult men, but around 1,000 are teenage boys or young men originally categorized as minors, and another 100 are women (some of whom are being held there with their children). The policy of holding any minors in such facilities has been rightly critiqued. 

The majority of this detainee population are Syrians, though a few hundred Iraqis and around 2,000 TCNs remain as well. The number of Iraqis has substantially decreased since 2021 because Baghdad has been actively repatriating them. Amid the latest crisis, the Syrian origin of many detainees has led to conflicting information about whether they are being held for their affiliation with IS or for other crimes defined by the SDF and DAANES. 

Most of these individuals have never faced trial, and gathering reliable information about them remains extremely difficult for numerous reasons, from security risks to the fact that nonstate actors run the facilities they are held in. As such, coalition forces have struggled to gather biometric data on all detainees, and NGOs are rarely granted access. 

Detention camps. Most of the remaining detainees in the northeast can be found at two closed camps with primarily women and children: al-Hol (which held up to 70,000 in 2019 but is now under 25,000) and the smaller Roj camp (with 2,400). The majority of those held at al-Hol are now Syrian, while the majority at Roj are TCNs. 

Here again, the Syrian origin of most al-Hol detainees has led to disinformation about why some are being held there. Not all of the camp’s residents are affiliated with IS; some were simply displaced by the multinational conflict with IS, so nuance is necessary when discussing how to resolve their situations. Moreover, the cases of TCNs who traveled to join the IS conflict must be handled differently than the cases of Syrian detainees. 

Iraqis were once the largest group at al-Hol, but that proportion has greatly decreased. Since 2021, Baghdad has brought more than 22,000 of its detainees home, carrying out thirty-three repatriation operations in al-Hol alone. This week, it responded to the latest violence in Syria by pledging to speed up its repatriation timeline and bring all of its citizens back.

Compared to detention facilities, repatriation and identification efforts are somewhat easier at the two camps because they tend to allow greater outside access and collection of biometric data. Governmental and nongovernmental organizations alike have repeatedly published clear, detailed statistics on who is there, where they are from, and who has been repatriated. Although the coalition has not released official numbers since June 2025, al-Hol’s current population is estimated just below 25,000, including 14,500 Syrians, 3,700 Iraqis, and 6,000 TCNs. These populations in al-Hol—coupled with the 2,400 TCNs in Roj and the estimated 9,000 IS fighters in detention facilities, around 2,000 of whom are TCNs—remain a real concern for Washington.

U.S. Policy Implications

The United States has been on the ground fighting IS forces in Syria since 2014, and helping to secure detention sites there since 2019. When the Assad regime fell in late 2024, the Trump administration took a forward-facing role in welcoming Syria back to the international community and facilitating discussions between the new government and the SDF. Those talks had been bogged down for months before fully breaking down this week. Through all this, the IS threat remains, as does the U.S. mission to counter the group. To continue carrying out that mission effectively while also preventing the current crisis from getting worse, Washington should take the following steps: 

Demand de-escalation. Given the Trump administration’s budding relationship with the new government in Damascus and America’s long working relationship with the SDF, U.S. officials need to make clear that neither side should take actions that undermine the vital mission of securing detention facilities and camps. Both sides need to take a breath—the recently announced temporary ceasefire is a good first step, but Washington needs to be explicit that if Damascus takes further unilateral steps, it will compromise U.S. support. Frank conversations are also needed about each side’s active spreading of disinformation, which puts the detention sites at greater risk. This message should also be shared with Syria’s neighbors, particularly Israel and Turkey, who each have their own agenda.

Work with Damascus and the SDF to secure detention sites. Although the Trump administration has made clear for months that it wants Damascus to take over all of these sites, it has been less clear about what that should look like in practice. Through the Counter-Islamic State Train and Equip Fund (CTEF), the United States has spent years and millions of dollars training SDF personnel to carry out the unique, complex mission of securing these sites, so they have the requisite knowledge and experience to handle this task. Yet current events have decreased the possibility of the SDF and Damascus working together and accelerated the timeline for transferring this responsibility to the Syrian government. U.S. assistance is urgently needed on securing these sites and creating the necessary training programs and networks, but such efforts cannot bear fruit overnight, and Damascus will have a sharp learning curve. 

Accordingly, the coalition should give Damascus information on where all the detention facilities are located and, ideally, who is being held there. At the same time, Damascus needs to ensure that local tribal actors are not preemptively clashing with the SDF elements who are securing these individuals. The coalition is also aware that SDF units withdrew personnel from al-Hol during the latest fighting, so Washington should urge them to stay at their posts and continue guarding the facilities. Notably, U.S. Central Command announced a new mission earlier this week to transfer up to 7,000 IS detainees to Iraq, suggesting that the Trump administration is wary of the current security situation and dissatisfied with the way both parties are handling the ongoing transfer of these sites.

Clarify the scope of the IS detainee problem. Over the past week, it has become apparent that Washington and Damascus may have differing definitions of who is an “IS detainee.” When Bashar al-Assad was in power, the problem set was divided into Syrians, Iraqis, and TCNs, and it encompassed both detention facilities and camps. Today, most Iraqis have been repatriated, and Syria has a centralized government that could theoretically handle the estimated 25,000 Syrian detainees. As discussions on this issue move forward, Washington and Damascus need to clarify if this problem set will continue to include all remaining TCNs and Syrian detainees, or just certain Syrian detainees (e.g., only men held in detention facilities). These decisions will affect not only the counter-IS mission, but also the direction of resources and international assistance.

Warn international partners that the detainee repatriation issue can no longer be delayed. Even before the current crisis in the northeast, the indefinite detention of thousands of individuals was not sustainable—not in security terms, and not in humanitarian terms either. Washington has long emphasized the need for repatriation and the consequences of delay, including IS breakouts. It has also set a good example by bringing home U.S. citizens who are IS fighters or family members, and by shouldering most of the financial burden for maintaining the detention sites. It is time for others to do their share—especially countries that still have citizens among the nearly 10,000 TCN detainees in Syria. Washington should compel these governments to repatriate their people, leaning on President Trump’s hard-nosed diplomatic style to convey that foot-dragging is no longer an option. The administration should also encourage Damascus to make this a key point in its engagement with these countries.

Devorah Margolin is the Blumenstein-Rosenbloom Senior Fellow at The Washington Institute and an adjunct professor at Georgetown University.