There is potential for ISIS foreign fighters captured in Syria to be tried by the International Criminal Court. If this proves possible, it could open up a pathway for it to exercise its jurisdiction in the broader context of the Syrian conflict.

Twenty years ago, a treaty established the International Criminal Court (ICC) with a mandate to end impunity for perpetrators of war crimes and prevent such atrocities. However, the reality is that the ICC has been largely ineffective in achieving these aims, because of deep flaws in its structure. Its inability to prosecute those who have committed war crimes in the Syrian conflict highlights these flaws. But, arguably, there are ways that the ICC could be more effective.

When protests erupted during the Arab Spring against President Bashar al-Assad’s repressive regime in March 2011, the government response was swift and brutal.

War crimes and crimes against humanity have been committed by all sides in the conflict – from the chemical weapons attacks on civilians by government forces to the use of civilians as human shields by ISIS fighters – the evidence is overwhelming. The Syrian civil war has now raged for almost eight years, while the United Nations Security Council (UNSC) has failed to reach consensus on any binding resolution, let alone a referral to the ICC. The conflict in Syria highlights the difficulty faced by the ICC in exercising its jurisdiction over individuals from states that have not ratified the Rome Statute.

Rather than an independent court with universal jurisdiction enabling the ICC to try any individual suspected of war crimes, the ICC instead requires that the UNSC, or a state where a national has committed a crime, refer cases. Membership of the ICC is voluntary. This means that if an individual from a non-member state commits any of the crimes within the ICC’s jurisdiction, it can only be investigated if the UNSC refers the issue. Yet such a referral requires consensus from the UNSC’s five permanent member states – France, the United Kingdom, the United States, China and Russia – all of which have the power to veto Security Council resolutions.

If one of these five states is strongly allied with the violating state, this referral is unlikely to happen, giving individuals from those states effective immunity from prosecution.  However, arguably, there are additional options for the exercise of ICC jurisdiction that should be explored.

Captured by US-backed Syrian Democratic Forces (SDF) in January, Alexanda Kotey and El Shafee Elsheikh from West London are among the 500-600 British fighters and represent half of the infamous group of ISIS members that became known as “The Beatles” due to their British accents. The pair are being held in Syria while they await the outcome of a legal challenge to determine their fate. Kotey and Elsheikh have drawn attention to a broader debate about what to do with foreign fighters and where they should face justice.

British Defence Secretary Gavin Williamson has declared that Kotey and Elsheikh had turned their backs on Britain and should not be allowed to return. If the United Kingdom refuses to accept the men, it has been reported they could end up at the US military facility at Guantanamo Bay in Cuba.

An option that has received less attention is that these men could fall under the jurisdiction of the ICC. One significant voice has called for Kotey and Elsheikh to be tried by the ICC, with UK Defence Minister Tobias Ellwood insisting in February 2018 that they should be sent for trial in The Hague.

Before assessing whether the ICC should investigate and prosecute Kotey and Elsheikh, it must be determined whether the Court can exercise its jurisdiction in this situation. Mark Kersten of the Munk School of Global Affairs at the University of Toronto has suggested that an ICC trial is possible, noting that “outsourcing is a part of complementarity and no doubt the ICC would like a slice of Syria accountability.” Under the principle of complementarity, the ICC can exercise its jurisdiction when a national court is unable or unwilling to act.

It seems reasonable to suggest that if two British nationals were to end up facing trial under the US justice system, that the United Kingdom has indicated that it is unable or unwilling to act.

The United Kingdom made the choice to join the ICC, and under its funding model is one of its largest contributors. In terms of gaining domestic support for a foreign policy decision, there appears to be a reasonable argument for referring Elsheikh and Kotey to the ICC. Williamson has said they have turned their backs on Britain and should not be allowed to return. So, as British taxpayers are already paying for the ICC in the Hague, it makes sense to try them there.

Their crimes have been widely acknowledged and often broadcast on the internet. They should surely face justice somewhere, so why not the ICC which was purpose-built to prosecute these types of offences? The ICC Prosecutor has previously clarified, in relation to a referral from Comoros, that it is the Office of the Prosecutor (OTP) that is solely responsible for deciding whether or not to open an ICC investigation in relation to state party referrals. So if the United Kingdom referred the situation, the OTP would be obliged to open a preliminary examination and would ultimately decide whether or not to proceed with an official investigation. At the very least, the issues of admissibility, including the gravity threshold, would be thoroughly and publicly tested.

It should be noted that this process could be undertaken by any ICC member state with foreign fighters captured in Syria, including Australia. While this would not necessarily lead directly to accountability for crimes committed by the Syrian regime, it would at least open the path for ICC involvement in the type of crisis it was supposed to help prevent.

This article was originally published by the Australian Institute of International Affairs.