Kurdish troops from the Syrian Democratic Forces stand in a forward operating base overlooking the frontline near the ISIL-held town of Hole in Rojava, Syria. (Photo by John Moore/Getty Images)

U.S.-supported Kurdish militia in northern Syria are detaining thousands of people. These include, according to the New York Times, suspected fighters, their families, and others such as “local civilians who were pressed by the Islamic State into administrative or medical jobs.” The New York Times also comments that the detainees “fall into a legal gray area,” explaining that “Kurdish authorities are parceling out justice in ad hoc courts, but the region is still part of Syria, and Kurdish control is not internationally recognized.”

The problem is these detainees don’t fall into a “legal gray area.”

That Kurdish militia, in this case the Syrian Democratic Forces (SDF), are detaining people and putting some of them on trial, certainly raises deeply complex legal issues, many of which can only be evaluated by assessing who is responsible for the detention operations and who is being detained. Once that is done, however, it’s clear that these detainees are in anything but a “legal gray area,” and that international law provides rules for the treatment and conditions of the SDF’s detainees, the procedures for their internment and trials, and their transfer to other authorities.

There are two types of armed conflict under international law. There are international armed conflicts (IACs), which take place between two or more states. Then there are non-international armed conflicts (NIACs), which take place between states and non-state organized armed groups, or amongst non-state organized armed groups. Once an armed conflict exists, international humanitarian law’s (IHL) wide-ranging rules become applicable. IHL’s rules for IAC are more elaborate than then IHL’s rules for NIAC, but the bottom line is that IHL contains rules on detention for both types of armed conflicts and those rules apply to all sides.

The SDF is a non-state organized armed group, fighting to similar ends as other states, that is in an armed conflict with the Islamic State, which is also a non-state organized armed group. For that reason, we’re dealing with a NIAC and anyone the SDF detains in relation to its armed conflict with the Islamic State receives the protections afforded detainees under IHL’s rules for a NIAC. These rules protect against things such as torture; cruel, humiliating and degrading treatment; and murder of people taking no active part in hostilities, including members of armed forces who have laid down their arms and those in detention.

IHL also provides rules on detention conditions, which requires providing them with adequate food, water, clothing, shelter and medical attention. The United States has acknowledged that the SDF has an uphill battle in an environment where at times it has been detaining 40 to 50 people a day. In response to this reality, General Joseph L. Votel has said that the U.S. military is working to improve the SDF’s detention capacity, including paying for improvements to SDF detention facilities.

IHL’s rules for NIAC also prohibit arbitrary detention and provide fair trial guarantees. For non-criminal NIAC detention (i.e., internment) not to be considered arbitrary, the justification must correspond to an exceptional conflict-related security threat. This means that anyone who is not suspected of posing such a threat should not be interned and anyone detained who is found not to pose such a threat must be released. The prohibition against arbitrary detention also means that a person must be notified of the reasons for his or her detention and should have the opportunity to effectively challenge the lawfulness of his or her detention.

According to the New York Times, Kurdish authorities have been trying to sort out which detainees to hold onto, such as Islamic State fighters, and which ones to release, such as local civilians who the Islamic State pressured into administrative or medical jobs. There is an underlying question of whether those local civilians (as well as suspected Islamic State family members) should have been detained in the first place, but the fact that the SDF is making such category distinctions reflects, at a minimum, that it recognizes that there are limits on whom it can and can’t detain.

There are also fair trial rules that the SDF must follow. The notion that a non-state armed group can administer a criminal justice system is, to say the least, an awkward concession for IHL to give [non-state actors] that don’t have any domestic legal authority to hand down sentences or lock people up. The reason IHL makes this concession is because one of IHL’s primary functions is to guard against the excesses of war, which have historically included flagrantly unfair trials. In that vein, IHL contains precise rules on how parties to a conflict—whether states or non-state actors—must administer trials. This includes, under Common Article 3 of the Geneva Conventions the prohibition on “the passing of sentences and the carrying out of executions without previous judgment pronounced by a regularly constituted court, affording all the judicial guarantees which are recognized as indispensable by civilized peoples.”

The two additional protocols to the Geneva Conventions also contain due process and fair trial guarantees.  Relying on them isn’t straightforward though. Protocol I isn’t applicable because it applies only to international armed conflicts and Protocol II doesn’t apply because Syria hasn’t ratified it and, therefore, the SDF isn’t subject to the protocol’s rules. But Article 75 of Protocol I does reflects customary international law, both in IAC and NIAC. A rule of customary international law emerges from a general and consistent practice of states that follow the rule out of a sense of legal obligation. Article 75 includes guarantees such as informing detainees of the allegations against them, the presumption of innocence, the right to remain silent, the right to be tried in his or her presence, and the necessary rights and means of defense. Therefore, as a matter of customary international law, the SDF is bound to these rules when it puts people on trial.

Odd as it may be for IHL to regulate how non-states actors hold trials, IHL doesn’t go so far as to grant non-state actors any rights to hold trials; it simply puts in place a set of rules for the SDF to follow if it decides to hold trials. This means that Syria could declare the trials null and void, release those who the SDF convicted, and prosecute the SDF for holding such trials.

IHL also regulates the choices non-state armed groups can make about whether it transfers detainees to other authorities.  This issue is relevant here because the SDF is holding a large number of foreign nationals and the United States is on record as wanting to see them transferred back to their home countries, potentially for prosecution. It is unclear which countries they might be repatriated to, but the New York Times piece leads with a photo of a Bahraini man. It’s also known that the SDF is detaining at least two British nationals.  More generally, researchers have identified a wide range of countries where so-called foreign terrorist fighters come from.

There is nothing per se wrong with repatriating people for trial. In fact, it’s a critically important part of holding IS fighters accountable for their crimes and providing justice for victims. But, under the principle of non-refoulement, there is a problem with transferring people to countries where they might face a risk of torture or other serious violations of human rights or international humanitarian law. This makes the non-refoulement principle yet another rule of international law that regulates how the SDF must treat its detainees.

Admittedly, there is no explicit non-refoulement principle in the IHL of non-international armed conflict. But under Common Article 1 of the Geneva Conventions, parties to an armed conflict must “ensure respect” for IHL, which includes, of course, ensuring respect for the prohibition against torture and other mistreatment. Referring to Common Article 1, the ICRC’s new commentary on the Geneva Conventions explains:

“If a Party to the conflict transfers a detainee to another authority, under the custody of which the detainee would be in danger of being subjected to a violation of his or her fundamental rights enshrined in common Article 3, that Party to the conflict would not have done all it could to ensure respect for common Article 3.”

The ICRC’s new commentary also explains that under Common Article 1 parties should monitor the fate of people transferred and that the transferring authorities should, if necessary, “exercise their influence in order to ensure observance of the Conventions by the receiving State.”

What about the United States?

With the SDF receiving so much U.S. assistance, does the United States have legal responsibilities to the detainees as well? There are three possible avenues to consider:

1) If it can be shown that the United States has a sufficient level of control over the SDF generally, or the SDF’s treatment of the detainees specifically, then the United States would be responsible for the treatment of the detainees under its own international human rights law (IHRL) and its IHL obligations.  While military officials tell the New York Times that the American personnel aren’t directly involved in building new detention infrastructure or guarding the detainees, there is high-level cooperation with the SDF. With respect to the detention operations alone, U.S. funding is being used to “erect fencing, put bars on windows and otherwise secure schools and other buildings being used as temporary jails.” (Due to length, this post doesn’t address the important issue of whether schools can or should be used as detention facilities.) The New York Times is also reporting that “United States Special Operations troops advising the Kurdish-led militia are cataloging fingerprints and other so-called biometrics” of the detainees and “American forces are also interrogating the detainees.”

2) Again, Common Article 1 of the Geneva Conventions contains an obligations to “ensure respect” for IHL. In so much as the United States is assisting the SDF in its detention operations, it must provide that assistance in a manner that ensures respect for IHL. In so much as the United States becomes aware of any unlawful detention practices by the SDF, the United States must, in the words of the ICRC’s new commentary, “do everything reasonably in their power to ensure respect” for IHL by the SDF and to prevent and bring IHL violations to an end.

3) Transferring detainees across international borders can be a logistically and bureaucratically complicated and frustrating endeavor, something I know from working on this issue at the U.S. Embassy in Kabul. We therefore shouldn’t be surprised if the SDF needs U.S. assistance in such things as high-level diplomatic negotiations, obtaining travel and identity documents, or getting the necessary flight approvals to send a person from one country to another. In conducting any of these activities, the United States would have its Common Article 1 obligations to consider in relation to the principle of non-refoulement – not transferring a person to a country where there is a real risk they will be tortured or otherwise mistreated.  The United States might have to play a direct role in the transfers, such as using U.S. aircraft to return SDF detainees to their home countries. If that happens, and the detainees come under the control of the United States, then the full weight of the non-refoulement principle falls on the United States.

International law contains legal gray areas. But such a claim needs to be carefully made. Doing so implies the law is silent, or inconclusive. Interpretative free-for-all’s can then ensue that undermine legal protections when they in fact exist. Detainees are in particularly vulnerable positions and it’s often because of what they’ve done or are suspected of doing that their rights are the first ones that states and non-state actors water down or ignore all together. In the case of the thousands of people that the SDF is detaining in northern Syria—some are suspected IS fighters, while others are family members and medical providers and civil servants coerced into working for IS—it’s clear however that no matter how you slice it, they do have legal protections and those responsible for detaining them have wide ranging legal responsibilities.