As international coalition forces seize the last vestiges of territory in Syria under the control of Islamic State militants since 2015, authorities in the United States, Europe, Russia, and Central Asia are grappling with a new dilemma.
How should they deal with their own citizens � both men and women -- who traveled to the Middle East to join the extremist group?
And what should they do about the hundreds of children born to such IS fighters and their brides?
Trump Says Take Them Back, Put Them On Trial
U.S. President Donald Trump has asked European Union countries to take back more than 800 IS (aka ISIS) fighters captured by U.S.-backed forces in Syria in order to put them on trial.
The caliphate is ready to fall, Trump tweeted on February 17. The U.S. does not want to watch as these ISIS fighters permeate Europe, which is where they are expected to go.
Trump's remarks followed a similar call from U.S.-backed Syrian Kurds who warned they don't have the resources to guarantee that captured IS fighters won't escape.
READ MORE: IS Fighter Husband Of Shamima Begum Wants To Take Her To Holland
Trump specifically called upon Britain, France, Germany, and other European allies to step up and do the job to ensure that captured IS extremists face trial in their countries of origin.
The alternative is not a good one in that we will be forced to release them, Trump tweeted.
But in the two weeks since Trump tweeted those remarks, many EU countries have said that captured IS fighters and their family members should be prosecuted where their alleged crimes occurred.
That means mostly in Syria or Iraq.
The European Commission says more than 42,000 foreign fighters joined terrorist organizations from 2011 to 2016 -- mostly the so-called Islamic State.
It says about 5,000 were thought to be from Europe.
EU foreign policy chief Federica Mogherini has ruled out any EU role in the repatriation dispute. She says the issue is one to be decided by national governments.
Britain Revokes Citizenship
British Prime Minister Theresa May's government has said IS foreign fighters should be tried where they are captured and, where possible, in the region where crimes were committed.
The case of Shamima Begum, a British-born schoolgirl who fled her home in London in 2015 at the age of 15 to join IS militants in Syria, illustrates how the dilemma is complicated by children born to IS couples.
In February, Begum gave birth to a baby boy whose father, an IS fighter, was killed in Syria.
After being sent to the Al-Hoq refugee camp in Kurdish-dominated northern Syria, Begum said last month that she wants to return to Britain for the health of her child.
But British Home Secretary Sajid Javid has ordered her British citizenship to be revoked and the British government has ruled out any effort to extract Begum and her child from Syria.
Meanwhile, since speaking out about her plight, Begum and her son have received death threats from others at the camp � forcing authorities to move her to another location closer to the border with Iraq.
Begum's case is not unique.
Two former London residents from an IS cell dubbed The Beatles also have had their British citizenship revoked after being captured in 2018 by U.S.-backed Syrian Kurdish fighters.
Alexanda Kotey and El-Shafee Elsheik are accused of beheading Western journalists and foreign aid workers in Iraq and Syria for IS propaganda videos.
The British government has said it does not want the two returned to the U.K. for trial -- a position opposed by Washington, which insists that terrorists' countries of origin keep responsibility for them.
Washington also has ruled out sending detained IS fighters to the U.S. military detention center in Guantanamo Bay, Cuba, where suspected terrorists have been detained indefinitely without trial.
Policy Shift In Paris?
More than 150 French citizens and their wives are now thought to be held by U.S.-backed Kurdish forces in northern Syria, the largest number of European IS fighters held in the country.
Concerned about the risk of repatriated fighters carrying out terrorist attacks in France, Paris has long refused to take back IS militants and their wives.
Foreign Minister Jean-Yves Le Drian has called them enemies who pose a threat to the nation.
Melina Boughedir, a 27-year-old French woman who joined IS fighters in Iraq in 2015, stood trial in 2018 in an Iraqi court that was fully backed by the French government.
Le Drian said it was normal logic for Boughedir to be judged where her actions took place.
But Trump's announcement of a pending U.S. troop withdrawal from Syria may prompt a policy shift in Paris.
In late January, French authorities said they were considering whether to bring back about 130 French IS fighters and their wives to put them on trial.
If the forces detaining these French fighters decide to deport them to France, they would be immediately handed over to the judicial authorities, Le Drian said after Trump's withdrawal announcement.
More than a month later, there still has been no apparent progress on French repatriations.
As for the children of IS fighters, French Justice Minister Nicole Belloubet says decisions will be made on a case-by-case basis.
In Germany, Foreign Minister Heiko Maas has said it would be extremely difficult to arrange the repatriation and prosecution of all German citizens who fought for IS.
Maas says returns would only be possible if authorities can guarantee that these people can be immediately sent to appear in court and that they will not be allowed to go free.
Some German authorities have expressed concerns that evidence against repatriated fighters may not be admissible in European courts and could lead to dangerous militants being freed.
Germany's Interior Ministry said in February that one-third of an estimated 1,000 German citizens who joined IS in Syria and Iraq since 2013 have returned.
Many, it said, have been prosecuted or enrolled in rehabilitation programs.
But Syrian Kurdish authorities say Germany is shirking its responsibility to repatriate Germans who joined IS, along with their wives and children.
Belgian Court Order
A Belgian judge on February 27 overturned a judgment forcing Brussels to repatriate two Belgian brides of IS fighters in Syria, saying the state is not obliged to bring them back.
Belgium's Justice Ministry said it still would take in the women's six children and any other IS children who are younger than 10.
The Belgian government said the children cannot be punished for crimes committed by their parents.
A Belgian court in 2018 convicted both mothers in absentia -- 26-year-old Tatiana Wielandt and 25-year-old Bouchra Abouallal � on charges of being members of IS.
Like France, Brussels has resisted calls for the repatriation of IS fighters and their wives.
But after the court ruling, Belgian Foreign Minister Didier Reynders said the government intends to repatriate children under the age of 10 whenever possible.
Ready To Repatriate
North Macedonia was the first European country to carry out a significant repatriation program from Syria and Iraq when it took back and prosecuted seven IS fighters in August 2018.
Russia also has repatriated more than 100 children and dozens of IS brides since August 2017.
A study published in 2017 by the International Center for Counter-Terrorism at The Hague praised Russia and Georgia for helping to repatriate family members of IS fighters.
That study says most IS children were exposed to horrific acts of violence -- including roles in execution videos -- and were desensitized to violence through endless indoctrination and paramilitary training.
It says Russia's repatriation policy calculates that it is better for the children to be raised in Russia by their grandparents than to grow up in refugee camps and, possibly, return to Russia as radicalized adults.
But the Washington-based Jamestown Foundation has warned that there is no short-term or long-term strategy for reintegrating returnees to Russia.
Instead, regional leaders such as Chechnya's Ramzan Kadyrov are simply using the process to paint a dovish picture of themselves for Caucasian Muslims, it says.
Since December, dozens of IS children have been flown to Moscow from Iraqwhere their mothers are imprisoned as IS extremists.
The Kremlin says all of their fathers have been killed on the battlefields of Iraq and Syria.
There also has been a steady trickle of former IS fighters and their families returning to their homelands in Central Asia in recent years.
Copyright (c) 2015. RFE/RL, Inc. Reprinted with the permission of Radio Free Europe/Radio Liberty, 1201 Connecticut Ave NW, Ste 400, Washington DC 20036.