How can we be sure that a terrorist group has been destroyed when not all of its fighters have been brought to justice and some may even be able to make their way to new arenas?

The answer to this question will determine the future of global counter-terrorism strategies in view of conflicting national priorities in the aftermath of the military successes to drive the Islamic State (IS) terrorist group, from key cities in Iraq and Syria.

When reports surfaced last month that two French women awaiting trial in Iraq over accusations of joining IS could be facing the death penalty, French Foreign Minister Jean-Yves Le Drian flew to Baghdad to express France’s opposition to any execution.

“As happens every time a French person is potentially condemned, we act very strongly to make our position known,” Le Drian told reporters during the trip.

Last week, a French court acquitted a man charged with harbouring the killers who had carried out the attacks in Paris in 2015 that left 130 people dead and dozens injured.

The presiding judge said the court had found Jawad Bendaoud not guilty of providing lodging to two of the attackers and helping them to hide from police when they were the most-wanted criminals in France.

While the court’s ruling brought a surprising end to the first criminal trial linked to France’s deadliest extremist violence in decades, the French government’s response to the trial of the French women in Iraq left more questions about France’s legal and practical considerations vis-à-vis anti-terrorism unanswered.

Moreover, it will definitely impact the future of the global war against terrorism, which is already being hampered by national political and security calculations and interests.

Some 30,000 to 40,000 foreign fighters joined IS before the group’s self-proclaimed caliphate began to crumble last year. Around 6,000 of these are believed to have come from Western nations, and there have been concerns that these individuals could now return home or move elsewhere and carry out further attacks.

Last week, representatives from countries in the US-led Coalition fighting IS met in Rome to discuss the fate of group detainees in Syria, but delegates were sharply divided on what to do with them.

One dispute between the United States and Britain centred around the fate of two British nationals accused of being IS militants who have been held by Coalition-backed Kurdish forces in Syria since mid-January.

Washington wants London to bring the two men to justice in the United Kingdom, but the British Defence Secretary Gavin Williamson says the men have turned their backs on Britain and should not set foot in the country again.

Thousands of IS fighters have already returned to their home countries amid confusion over whether they have been jailed or are being tracked. Many have disappeared from the view of the security services, which have often not disclosed information on such fighters’ legal status for joining a terrorist organisation.

Turkish police have routinely been reporting the detention of foreign citizens crossing the country’s borders with Iraq and Syria over suspected links to IS, but little is known about whether these are now facing prosecution.

Thousands are believed to have surrendered to Kurdistan Regional authorities in northern Iraq, but there has been little news about plans to prosecute them or send them for trial in Baghdad.

While the fate of the detainees or returnees underscores a serious problem, the controversy could go beyond tackling the challenge of terrorists captured in the war to those who managed to run away from the battlefield.

In November, a BBC report disclosed that the US-led Coalition had allowed some 4,400 suspected terrorists to leave the besieged Syrian city of Raqqa with their families in a convoy going towards the Iraqi border.

In June 2016, some 1,000 militants, including senior IS leaders and some foreign fighters and their families, succeeded in making their way out of the besieged Iraqi city of Fallujah, escaping the aerial bombardement of their convoys by the US-led Coalition.

The US-led Coalition is not the only party to suspicious deals that have allowed thousands of IS fighters to escape arrest or prosecution. In August 2017, some 300 IS fighters and family members were transferred from the Lebanon-Syria border to new locations in IS-controlled territories under a deal with the Lebanese Shia group Hizbullah.

This shocking revelation was not unprecedented. Hundreds of terrorists were also allowed to go free during the battle to retake Mosul and other cities in Iraq last summer. Kurdish Peshmergas forces said they had arrested some of the escapees who were trying to make their way to Syria and Turkey.

The controversy over the IS fighters has triggered concerns that parties to the international war against IS lack a coherent strategy to track returning militants and bring them to justice.

The United Nations and human rights groups have criticised Iraq’s execution of prisoners charged with affiliation with IS, accusing the Iraqi government of displaying “disregard for human life and dignity”.

Their criticism centres around either “flaws in the Iraqi justice system” or a lack of “credible evidence that the death penalty deters crime more than a term of imprisonment.”

The UN and the rights groups have also charged the Iraqi authorities with abuses against prisoners accused of terrorism offences and demanded guarantees of fair trials.

While such criticism is based on moral grounds and attempts to ensure the protection of human rights, it falls short of providing concrete and practical proposals for punishments that reflect the seriousness of the crimes perpetrated by the terrorists.

With the parties differing on how to deal with such challenges, including whether suspected militants should face trial in the countries where they committed their crimes or be sent home for prosecution, the United Nations now needs to come up with a tangible legal strategy for global counter-terrorism.

Under several UN resolutions, member states are required to “bring terrorists to justice through effective criminalisation,” but nothing has been offered to establish well-defined guidelines on the prosecution of “foreign” terrorists, for example.

The latest flash point about the two British terrorists and the debate over whether they should be returned to their country of origin for trial or tried in the countries where they operated highlights the need for an international mechanism for such trials.

It is evident that some countries are reluctant to take responsibility for their nationals who joined IS and participated in atrocities against foreign nations for selfish reasons or national priorities, such as the fear of a backlash at home or retaliation by terrorist groups.

While the complexities arising from bringing foreign terrorists to justice pose new challenges, the bigger dilemma that the world could witness if no action is taken dictates the need to address the problem and determine where such individuals should face trial.

In September, the United Nations Security Council approved the creation of a UN investigative team to “collect, preserve and store evidence” in Iraq of acts by IS that may be “war crimes, crimes against humanity or genocide.”

Although the UN Resolution puts a cap on the inquiry, its scope could be expanded to provide a legal framework for concrete action to face up to the threat that returning foreign fighters could present to the wider world.

Under UN Security Council Resolution 2379 (2017) evidence of crimes collected and stored by the investigation team in Iraq “should be for eventual use in fair and independent criminal proceedings conducted by competent national-level courts.”

Ironically, the Iraqi diplomacy which under British pressure requested the resolution, has thus far failed to make the Security Council act to develop international capacity to try IS combatants and provide justice to their victims.

As long as Western nations continue to show hypocrisy and incompetence in confronting this challenge and refuse to accept the return of their nationals to face trial, the world will face the real danger that the terrorists will travel to other countries to carry out more attacks.

* This story was first published in Al-Ahram Weekly