Paris (AFP) - France has raised the prospect of repatriating around 50 jihadists detained in Syria, creating a domestic political storm that highlights the difficulties posed by bringing extremists home.
Successive French governments had insisted citizens who left to live or fight under the Islamic State group in Syria or Iraq should face justice locally, apart from children who could be returned without their parents.
But concerns about the possible release of the detainees by Kurdish-led forces in northeast Syria have forced a rethink which could see around 50 men and women returned to France, as well as 80 children, according to sources who have spoken to AFP.
The United States on Monday called on other nations to repatriate and prosecute their nationals.
Here are five key issues:
- Relocation -
The first problem is working out how the suspects would travel from the prison camps, which are run by Kurdish-led Syrian Democratic Forces (SDF), the main fighters on the ground combatting Islamic State.
There is no recognised government in the SDF-run areas between Iraq and Turkey, and the area is highly unstable because of the threatened withdrawal of US troops and a possible offensive by Turkish forces.
French special forces are known to operate in the area, alongside the Americans, who have helped train and back up the Kurds with air support.
"We are looking at all the options: we could bring them to another country, bring them back directly from Syria, or negotiate with Turkey," a French official said on condition of anonymity.
French Interior Minister Christophe Castaner has talked about the fighters being "expelled", rather than being brought back, but expulsions can normally be carried out only by a sovereign state.
- The evidence -
Like other European countries, France has repeatedly tightened its anti-terror legislation, most recently under current President Emmanuel Macron in 2017.
The problem for prosecutors is finding the necessary evidence from a foreign battleground that can withstand scrutiny in national courts.
"Work is being done together (between various French ministries) with the utmost care. We don't want to risk any procedural problems which would allow any of them to be released once they get back to France," the French official added.
Some extremists might have appeared in IS propaganda videos or had their communications intercepted, enabling the serious charge of joining or leading a terror organisation, which can lead to a 30-year prison term.
But in other cases, where prosecutors lack direct incriminating evidence -- in the case of wives who accompanied their husbands, for example -- they might have to fall back on the catch-all charge of "associating with terrorists," experts say.
- The judicial system -
Despite increased resources, specialised anti-terror prosecutors and the French court system are already struggling to deal with the surge in terror cases since IS declared its caliphate in 2014.
Experts say that hundreds of an estimated 1,700 French nationals who went to Iraq and Syria have already returned home, often ending up in court.
"The judicial system is going to have to adapt to cope with this very large number of jihadists," Jean-Charles Brisard, chairman of the Center for the Analysis of Terrorism, told AFP.
He added that France's "Cour d'Assises", where the most serious crimes are tried, "lacks resources."
"It's not sufficiently staffed for the number, the volume of jihadists," he warned.
- The prison system -
The new arrivals would also put pressure on the French prison system, where overcrowding and difficulties in dealing with Islamist inmates are long-established problems.
Marc Hecker, a security expert at the IFRI think-tank in Paris, estimates there are around 500 people in jail in France on terror charges who have already been sentenced or are awaiting trial.
"It's very difficult to handle these people in jail. You have to separate them from the rest of the inmates," Hecker said. "Or you can let them be with the other inmates and they may radicalise other people."
The detainees would be assessed by French psychologists for four months when they enter the prison system, and the most dangerous would be placed in solitary confinement.
In January last year, prison guards undertook the biggest strike in a quarter of a century to demand better pay and conditions, and to protest against the dangers of radicalised inmates.
- Children -
Of the 130 people who might be repatriated, most are thought to be minors who are likely to face major psychological problems.
"These are children who were born over there or left France very young with their parents," Justice Minister Nicole Belloubet said on Thursday, adding that some of them are orphans.
"We think that around 75 percent of the children are under age seven," she added.
Once back in France, they would be separated from their mother or father, who would be jailed, adding to their trauma.
A child's case would then be assessed by a family judge, who must decide whether to place them with relatives, or with a foster family.