EVERY day their numbers grow. There are now more than 1000 in detention according to the most recent estimates, and those are only a result of the latest fighting.

Last Wednesday more than 200 members of the Islamic State (IS) group – most of them foreign fighters – holed up in the enclave of Baghouz in eastern Syria gave themselves up.

Thousands more women and children, many of them the wives of these same IS cadres, are already cramming the camps set up for those displaced, as the jihadist terror group disintegrates in the last slither of territory that remains of its once self-proclaimed caliphate that spread across swathes of Syria and Iraq in an area roughly the size of Britain.

And speaking of Britain, back here right now it takes a lot to get people talking about a news story beyond Brexit, but the ongoing debate over what should be done about Shamima Begum – the former British schoolgirl who joined IS in 2015 and now wants to return to the UK from Syria – is one such story.

For the past week the issue of whether the nine-month pregnant woman now aged 19 should be repatriated has polarised British public opinion. The debate over her fate is not the first and will certainly not be the last over what do with foreign fighters and supporters of IS as the detention camps of northern Syria fill up and the challenges posed likewise mount up.

With so much polemical heat surrounding the Begum case, it’s perhaps worth stepping back and pausing for a moment to cast some badly needed light on this controversial issue.

For it’s precisely at this moment that so many complex and serious questions need well thought out solutions if an already pressing and dangerous situation is not to be made worse.

To begin with, this is not a problem that’s going anywhere fast. It’s thought that up to 41,490 international citizens from 80 countries joined IS in Iraq and Syria between April 2013 and June 2108, according to a report by the highly respected International Centre for the Study of Radicalisation (ICSR), at King’s College London, published last year.

To put this in some context and perspective, currently on the ground the Kurdish-led Syrian Democratic Forces say they are struggling to cope with the responsibility of holding IS detainees from 50 countries that they have in custody.

“We can’t do it alone,” says Abdulkarim Omar, a leader of the Kurdish-led foreign-relations commission, which is affiliated with the US-backed Syrian Democratic Forces (SDF). “Everyone is running away from the responsibility,” he insists.

There is little doubt that the Kurds’ fledgling administration lacks the resources and capacity to put on trial, or detain indefinitely, so many people. It’s vital too that they are in a position to carry out detentions under humane and sustainable conditions over an extensive period of time, something that cannot be done without advice and support from foreign states and international bodies.

In Syria’s Kurdish enclave, the leftist ideology embraced there means a rejection of the death penalty and a focus on rehabilitation rather than punishment for those foreign fighters captured. This is different from Iraq, where the Western-backed government often carries out the death penalty, earning the condemnation of Western human rights groups.

Last week Iraqi Prime Minister Adil Abdul-Mahdi said Iraq will repatriate Iraqi IS members held by SDF in Syria as well as thousands of their family members. A senior Iraqi intelligence official told reporters that up to 20,000 Iraqis, including IS fighters, their families and refugees, will be brought back home by April where many of them will live in a tent settlement in western Anbar province.

The official, who spoke to the Associated Press on condition of anonymity because he was not authorised to speak to the media, said IS members will be interrogated by Iraqi security agencies, a move that will give human rights groups cause for concern as to their potential fate.

For the moment, though, it’s Syria’s Kurds that are shouldering most of the burden when it comes to dealing with the crisis. Faced too with uncertainties over their own future because of the impending withdrawal of US troops and the threat posed by Turkish forces, they remain caught between a rock and a hard place both politically and strategically over those IS captives they have taken.

“They are being held in an area that is not stable and any vacuum or chaos could allow them to break out of prison and it would be a burden and big danger,” warns Abdulkarim Omar.

These past weeks have only underscored such arguments and the transnational scale of the problem captured foreign fighters present. Russians, families from central Asia, Ukrainians and Canadians were all reported to be among those to have fled Baghouz recently, providing a sharp reminder of the global scope of the IS jihadist organisation.

The National: A young boy who has fled fighting in Bagouz looks out the back of a truck, being transported to a camp after they were screened by members of the Syrian Democratic ForcesA young boy who has fled fighting in Bagouz looks out the back of a truck, being transported to a camp after they were screened by members of the Syrian Democratic Forces

A little less than a fortnight ago, as the Baghouz operation intensified, six foreign jihadists of various nationalities who had actively participated in the terrorist activities of the group for years were also captured, the SDF confirmed in a statement. The men are reportedly from Russia, Germany, Turkey, Sweden, Morocco and an unspecified country in Latin America.

Though you could be forgiven for thinking so going by some media reports, the case of British woman Shamima Begum is far from unique.

Among the civilians fleeing Baghouz recently was a German woman who also came to live under IS as a 15-year-old. Meanwhile, a woman identified by a French news agency as Leonora, now 19, escaped to a screening centre for the displaced where she described travelling to Syria two months after converting to Islam. She became the third wife of a German IS fighter named Martin Lemke, bearing him two children in Syria. Her husband was detained by the SDF after the family fled the fighting. “We gave up together,” she said.

Faced with such a diverse range of nationalities, Kurdish officials have reached out to all countries with citizens in detention, but few have responded.

Kazakhstan, Russia, Sudan and Indonesia have repatriated some families. At least one American, a woman, and an Iraqi woman have also been returned to their countries, says Kurdish foreign relations spokesman Omar.

A huge part of the problem, of course, is that it’s near impossible to come up with a one-size fits all solution to what overall could be as many as 3000 plus people the SDF and Kurdish authorities are holding.

Amarnath Amarasingam, a senior research fellow for the Institute of Strategic Dialogue, recently told the Washington Post after visiting north-eastern Syria and interviewing detainees that many governments, especially Western ones, take the attitude that those who chose to join IS surrendered their citizenship rights when they decided to leave their countries, “The broader argument is: You went over there, you renounced your citizenship, and you joined an organisation that gave no second chances to anyone,” he said.

Added to this are the understandable concerns of some foreign authorities that returnees might not be genuine in their remorse and could spread radical ideology or plot future attacks, says Amarasingam.

Some observers, however, see this as a “distracting fear”. Joseph Horowitz, senior legal officer for the Open Society Justice Initiative, whose specialisms include human rights, national security and counter-terrorism, says that first and foremost people “need to be assessed on an individual basis rather than be subjected to collective assumptions and attitudes that are one step away from a presumption of guilt”.

The National: Civilians who have fled fighting in Bagouz wait to board trucks after being screened by members of the Syrian Democratic ForcesCivilians who have fled fighting in Bagouz wait to board trucks after being screened by members of the Syrian Democratic Forces

RADICALISATION, Horowitz argues, remains in many instances undefined and is often injected with discriminatory religious and cultural stereotypes about who performs “radicalisation”, who can be “radicalised” and what constitutes indicators of “radicalisation”.

Such observations will do little to allay the fears of those already uneasy about the labyrinthine legal terrain that exists over returnees. In many instances, for example, it’s far from clear whether there would be enough evidence to prosecute and imprison many of those coming back, especially in Western countries where evidentiary standards are high. In this respect the chaos in Syria works in the favour of returnees.

Ali Soufan, a former FBI investigator who now runs the Soufan Centre, dedicated to the de-radicalisation of extremists, says that unless they were well-known figures or featured in videos committing war crimes as in the case of British Arab Mohammed Emwazi, nicknamed “Jihadi John”, it would be difficult to make any charges other than minor ones stick.

Some returnees, says Soufan, might also claim they only travelled to help fellow Muslims in distress and were unaware of IS’s atrocities, a claim that on more than one occasion has already been made by those choosing to come back from Syria and Iraq. Such legal conundrums are only set to increase as the number of returnees also gains momentum.

Already Western European countries have seen a total of 1765 nationals return, according to the ICSR study. In another analysis of six EU countries, carried out by the European Parliament (EP), half of those who left the UK have returned, the highest rate among the six countries examined.

By and large, though, the pattern by which IS returnees are dealt with in EU countries is based on criminal investigation and risk assessment. Rehabilitation and reintegration schemes have also been introduced inside and outside prison. Other measures include restrictions on movement and powers to withdraw and refuse to issue passports.

For some time here in the UK, the Government has been seeking to block the return of anyone considered a security threat, using a range of legal powers.

Many of the known IS members who were dual nationals have had their British citizenship removed, like members of the “Beatles” cell of which Mohammed Emwazi was part before his death. This citizenship removal invalidates their travel documents and means the UK can avoid responsibility for repatriating them from Syria or future legal proceedings. The most recent official statistics show that 104 people were deprived of British citizenship in 2017 and 14 in 2016.

The power has been used for criminals as well as terrorists, and the law allows it in cases “conducive to the public good”. But making a person stateless is against international law, so it can only be used for dual nationals, and last November two cases were ruled unlawful.

Then there is the use of temporary exclusion orders (TEOs), which are imposed by the Home Secretary and make it illegal to return to the UK without notifying authorities. Subjects could also be put on “no-fly” lists, ensuring that their return is flagged, and they then have to abide by conditions such as reporting to police or entering de-radicalisation programmes.

In the coming weeks and months, the use of all these measures will be stepped up as the UK Government seeks to reassure a nervous public.

“Any British citizen who does return from taking part in the conflict must be in no doubt they will be questioned, investigated and potentially prosecuted,” Theresa May’s official spokesperson was at pains to point out last Thursday as the furore around Shamima Begum intensified.

Speaking around the same time, while attending the Munich security conference, Alex Younger, the head of Britain’s Secret Intelligence Service (MI6), warned that IS’s threat is likely to “morph and spread” and that the danger it poses is “definitely not done”.

He cautioned about showing triumphalism at the demise of IS.

“The military defeat of the caliphate does not represent the end of the terrorist threat that we face,” he said.

Like it or not, dealing effectively with returnees will play a vital part in neutralising that threat. This is not the time, as many have suggested, to say “let them rot” in Syria. For most likely they will not rot, but instead be recycled into the jihadi cause.