The goal of establishing an international tribunal to prosecute ISIS fighters is gaining momentum in European capitals, however, whether this aspiration can be translated into a credible policy remains to be seen

The idea of setting up an international tribunal to try fighters from the Islamic State group (ISIS) is gaining momentum in Europe. Sweden, whose interior minister has been promoting the concept in European capitals, will host a meeting of European officials to discuss the initiative on Monday. The Dutch foreign minister plans to bring the idea to the United Nations in the autumn. This flurry of activity testifies to EU governments’ intense desire to find some way to deal with the hundreds of European ISIS supporters and their family members detained by the Kurdish-led Syrian Democratic Forces (SDF). An international tribunal is an attractive idea in many ways, but it does not offer an easy or complete solution to the dilemma these governments face.

The SDF holds an estimated 800 European ISIS fighters in makeshift prisons, as well as a larger number of related women and children in refugee camps, in north-eastern Syria. European countries are reluctant to bring many of these people home because of the difficulty in prosecuting them domestically and the security threat they are thought to pose. European fighters account for only a fraction of the thousands of fighters and their family members the SDF holds. Claiming that it lacks the capacity to prosecute or continue holding these prisoners, the Kurdish administration in the region has called for an international tribunal to pass judgement on them. Some human-rights advocates have also called for an international court to prosecute ISIS fighters for their crimes.

There is no question that ISIS forces are responsible for atrocities on a massive scale: The ISIS campaign against the Yazidi minority in Iraq is widely described as genocide, and the group has routinely tortured, enslaved, and killed those under its control. Nevertheless, there would be many complications in setting up a tribunal. The first is the scope of the initiative: would it cover crimes by only ISIS or all jihadists, or all war crimes committed in Syria? Leaving the Syrian regime’s atrocities out of the picture would seem anomalous – given their scale – but this would surely be a prerequisite for launching a tribunal. Russia and the United States would strongly oppose any tribunal that investigated pro-regime forces or the anti-ISIS coalition respectively. As such, European officials have suggested that the tribunal’s backers could widen its remit later if the circumstances allowed.

Then there is the question of the tribunal’s geographical location. The justification for establishing a new body is that it would sit in the region, close to the group’s victims and potential witnesses. But it appears impossible to set up an international tribunal in a part of Syria controlled by a non-state group, without the consent of the Syrian government. For this reason, European governments are now looking at the option of basing the tribunal in Iraq. This could be either a fully international “ad hoc” tribunal, such as those established for the former Yugoslavia and Rwanda, or a hybrid domestic-international body, such as the Special Court for Sierra Leone.

An international tribunal could only prosecute members of ISIS for international crimes – genocide, crimes against humanity, and war crimes. These are certainly the most serious crimes that ISIS forces committed, but it is unclear how easily their responsibility for such offences could be proved in court. If the testimony of captured members of the group is to be believed, the ranks of ISIS appear to have been largely composed of ambulance drivers – as European officials sardonically note. Indeed, it is the difficulty of proving involvement in violence that deters most European countries from prosecuting their foreign fighters at home. Holding trials in the region might make it somewhat easier to build cases, but it would not resolve the broader problem.

A hybrid Iraqi-international tribunal could prosecute some crimes under Iraqi law, perhaps including mere membership of ISIS, but this would create additional challenges. For a start, the approach would seemingly allow prosecutors to press charges for ISIS membership under Iraqi law against only defendants who had been active in Iraqi territory. Moreover, such a court would appear to violate Iraq’s 2005 constitution, which expressly states that “special or exceptional courts may not be established”.

And, finally, Europe would have a problem with the death penalty. Capital punishment is permitted under Iraqi law, but European support for, or involvement with, a tribunal that could apply the death penalty would be out of the question. France is currently grappling with a growing public outcry about death sentences passed on French citizens who were transferred from Syria to Iraq for trial – with the French government apparently seeking to have the sentences overturned.

Addressing all these complications and setting up a tribunal will hardly be a quick affair. The court would not begin to hear cases for several years. It would also be an expensive undertaking and likely limited to prosecuting a minority of European foreign fighters. The United States appears to be opposed to the move, which would block the most straightforward way to establish the tribunal: through a UN Security Council resolution. Moreover, the tribunal’s backers would need to be prepared to repatriate any of their nationals who were acquitted.

For the moment, Europe’s newfound enthusiasm for an international tribunal remains more a political aspiration than a well-developed and credible policy. Next week’s meeting may start the process of transforming this aspiration into a clearly defined project that can decide between the different options and generate support for a path forward. A tribunal would provide a powerful way of ensuring that those most responsible for the crimes of ISIS were held accountable. But it would not generate a magical solution to the problems posed by the broad mass of European fighters and ISIS supporters in Syria. Europe should not put off the task of devising other ways to handle the detainees while discussions on an international tribunal gradually advance.

Read more on: The Middle East and North Africa, Syria / Iraq / Lebanon, IS, Syria