Seemingly endless lines of Islamic State fighters streamed out of the group's last pocket, Baghouz, last weekend as US-backed fighters from the Syrian Democratic Forces rendered the thin strip of riverbank into a surrealistic sea of empty tents and abandoned cars.

By Saturday morning, defeat was finally announced.

However, despite the hardline Islamist group’s territorial defeat in Syria, the international community and Kurdish-led authorities in eastern Syria now face myriad new challenges in dealing with a post-Islamic State (IS) transition—including what to do with thousands of foreign fighters who are quickly filling Syrian Democratic Forces (SDF) detention centers to capacity.

This challenge is one that the international community is woefully unprepared to handle, according to Human Rights Watch’s Terrorism and Counterterrorism Program director, Nadim Houry.

“There’s still no [clarity] in terms of how to try foreigners,” says Houry.

What if they had actually caught [IS leader Abu Bakr] al-Baghdadi? What if they still do [catch him]? Who is actually going to try him? With what laws? No thought has been given to this.”

In a recent Guardian article, Houry argued that the “lack of preparation for what comes after [IS] is shocking,” drawing from what he witnessed in areas of eastern Syria.

With the SDF and Kurdish-led Self-Administration authorities in eastern Syria either ill-equipped—or unwilling—to handle the volume of IS suspects, the fate of foreign fighters remains particularly unclear.

Many are now stranded in SDF-administered detention facilities or displacement camps. Both the UK and US have meanwhile stripped foreign fighters, and foreign women associated with the hardline group, of their citizenship in recent weeks.

At the same time, there have also been instances of foreign fighters being transferred to Iraq for prosecution. In one such case, in recent weeks, up to 14 French former IS fighters were reportedly transferred to Iraq where they faced trial and ultimately confessed to being members of a terrorist organization.

Transfers are being conducted with little to no transparency, human rights groups say.

The Iraqi judiciary system has meanwhile been the subject of torture allegations, insufficient evidentiary standards, and a somewhat lax definition of what constitutes terrorism as a crime: any material support for a terrorist organization.

Syria Direct’s Tom Rollins spoke with Nadim Houry to get a deeper insight into the human rights challenges facing eastern Syria in the wake of the territorial defeat of IS.

“When things happen in the dark, there’s a higher risk that abuses occur,” Houry says, calling for a “transparent process where, first of all, people should not disappear.”

Q: You were in eastern Syria not long ago, and you wrote about a ‘lack of preparedness’ for what comes after IS there. What does that lack of preparedness mean for transitional justice in these areas?

It’s exactly the same issue. It connects first in terms of [the fact that] to this day, there’s still no [clarity] in terms of how to try foreigners. What if they had actually caught [IS leader Abu Bakr] al-Baghdadi? What if they still do [catch him]? Who is actually going to try him? With what laws? No thought has been given to this.

But even mid-ranking or lower-ranking [IS members], or foreigners. We’re still seeing this. They still have not developed a policy.

It’s not like they said, ‘Okay, we’re going to set up a special tribunal somewhere, and we’re going to invest in it.’ It’s not like they said, ‘We’re going to create a UN-mandated tribunal for the high-ranking guys.’ Or that they said, ‘We’re going to invest in local tribunals in northeastern Syria.’ None of that has taken place. There’s just been absolutely no planning, no vision.

[And there is a] complete lack of preparedness to deal with the outflow of civilians, basically many of whom were the families of IS members—including the children. This is the situation that they find themselves in now with these camps, in Al-Hol and others: sanitary conditions are terrible; the children themselves are coming out of the IS pockets in weakened shape.

France finally repatriated five children who were isolated in the camps—as in, their mother had died, and if they had a father, their father was in detention. But there are dozens and dozens more. We’re talking about hundreds of children, most of them very young, in terrible conditions.

There’s a complete lack of strategy for justice, and the net result is that victims are not having their day in court—be they local victims or international victims. Suspects are not having their due process respected; victims are not participating.

And in northeastern Syria, there are no trials for the foreigners, period. The [Kurdish-led Self-Administration] don’t want to do that because they see it as too much of a burden for them, and they don’t have the capacity. And frankly, their counterterrorism courts in northeastern Syria are not equipped.

Q: You mention that there’s this lack of capacity, or lack of will, on the part of the Self-Administration to try these cases of foreigners in northeastern Syria. Can you explain?

On the issue of courts in northeast Syria: [the Self-Administration] have courts dealing with terrorism—they’re called People’s Protection Courts, to be distinguished from People’s Courts, which are the usual civil courts.

So why are these counter-terrorism courts not equipped, and overwhelmed? It’s a mixture of reasons.

There were very few local judges that remained in northeastern Syria after the regime pulled back.

[Ed.: With the exit of Syrian army units from Kurdish areas of northwestern and northeastern Syria in 2012, Kurdish armed groups and authorities, including the Self-Administration, established their own parallel forms of governance.]

[The Self-Administration] have built up their own system but, like many things in northeastern Syria, they’ve built it bottom-up. They have not received many resources, and they have not invested that much in building it up.

In northeastern Syria, [local authorities] tried to be participative courts, but they have ended up with a very rudimentary system. The motivation may be interesting, but it raises all sorts of due process concerns. Defense lawyers play no role in the proceedings and there is no formal appeal. Such courts cannot comply with international due process standards.

On the positive side, they abolished the death penalty. They adopted a pretty simple [counter-terrorism] law, which was basically on a page and a half, but really they’ve been focused on prosecuting Syrians.

They’ve said they don’t want to worry about the foreigners, because it’s not their priority and they don’t know what to do with them.

Q: What about foreign fighters who’ve been transferred to Iraq? Can you talk through the legal process for transferring foreign nationals to Iraq?

We were the first to raise the alarm about these transfers last year when we found a few cases. And now, they’ve continued and are increasing. We actually wrote at the time to the US, the Iraqis and the SDF, asking them, ‘How is this happening?’ And no one would answer us—I think because they’re trying to do it in the dark on purpose. So right now, these transfers are not taking place within any legal process.

We believe that the first transfers were definitely coordinated by the US, based on what people were telling us. If the US sends someone to torture, they’d be violating their own obligations under the Convention Against Torture.

A couple of weeks ago, there were reports of the transfer of 13 or 14 French [fighters]. Again, how did that transfer happen? Why were these French [nationals] identified? [Was it] with the role of France, or not?

Nobody is commenting on this. Nobody is giving information on how that’s happening, and who’s coordinating it and who’s deciding who gets transferred to Iraq.

When things happen in the dark, there’s a higher risk that abuses occur.

[But] there’s no reason for this. There should be a transparent process where, first of all, people should not disappear. There should be a clear designation, clear judicial process, to provide justice for the victims and to hold people accountable.

Q: What’s the legal process waiting for foreign fighters once they are transferred to Iraq? What are some of your concerns about that process?

In Iraq, there are prosecutions under the Iraqi counter-terrorism law. They’re applying it to Iraqi nationals but also to foreigners: men and women.

With the Iraqi law, there’s two outcomes: either the death penalty or life in prison for membership of a terrorist organization.

[HRW] raised all sorts of due process issues in relation to: confessions obtained under duress; the speed through which these trials have taken place; the fact that there’ve been intimidations meaning that very few Iraqi lawyers will take these cases. Suspects do get named a lawyer but the lawyer usually becomes aware of the file the morning of the trial, so there’s no real defense planned.

There’s no differentiation in the law or in practice between different levels of actions. There’s been no participation of any victims in these trials: Yazidis, other Iraqi victims, foreign victims. So the victims are completely absent from the trial.

And children can be prosecuted from as young as age nine.

Q: When it comes to these transfers to Iraq, do we have any sense of scale?

We don’t have numbers, because these transfers are being done in secret. Most people don’t know if their loved-ones, relatives or husbands have been transferred.

Some, we find out about by chance after the fact because they appear in court in Iraq. Some have been able to send letters...to their families [as] regular prison mail and the families discover that the letter was sent from Iraq.

Our main demand is for more transparency because we don’t know how many people are being transferred.