Leaving Shamima Begum and other former Isis members in Syria could be more dangerous than allowing them to return to Britain, the government has been warned.
Officials are fighting a court ruling that Begum, who left the UK when she was 15, should be allowed back into the country for a legal battle over the removal of her British citizenship.
The same power of citizenship removal has been used against dozens of British jihadis who joined Isis, including several who are currently in the custody of the Syrian Democratic Forces (SDF).
Maya Foa, director of the legal charity Reprieve, said the current situation was “untenable”.
“Britain is putting its head in the sand about the safety and security concerns of a large number of British children, as well as the prospect of justice for the adults,” she told The Independent.
“It was the former director of MI6 who said leaving them there is more dangerous to British national security than bringing them there, and it’s obvious to see why.
“You have unstable camps, held by a non-state actor in a pretty fractious region where we know there have been escapes. They could very well be back on battlefields. That’s not a good option from a security perspective.”
Kurdish officials have repeatedly called for nations to repatriate foreign fighters and warned that they could not guarantee the security of prisons and detention camps after the Turkish-led invasion of northern Syria in October.
Some MPs have raised similar concerns, including a former Conservative defence minister.
Tobias Ellwood accused the government of “walking away” after joining the US-led coalition to bomb Isis territories.
“Tens of thousands of hardline fighters and families are held by a militia we trained – now under siege from Turkey,” he wrote on Twitter. “Daesh is escaping, regrouping and will attack the West again.”
Mr Ellwood previously told The Independent the detention of thousands of jihadis and their families in Syria was creating conditions for an Isis resurgence.
“We’ll see Daesh 2.0,” he warned. “We’ll see a repeat of al-Qaeda regrouping and becoming a very real threat, and that threat won’t just pose itself in the Middle East, but also to Britain.”
In 2016, a report commissioned by the UK government concluded that removing extremists’ citizenship may be an “ineffective and counter-productive weapon against terrorism”.
The Independent Reviewer of Terrorism Legislation, then Lord Anderson, was asked to review changes to the law that allowed the home secretary to strip naturalised British citizens of their nationality, even where they would be made stateless.
His report said: “A citizenship deprivation power has been characterised as an ineffective and counter-productive weapon against terrorism.”
It quoted research by academics in Canada saying it amounted to “a policy of catch and release, setting up today’s convicts as tomorrow’s foreign fighters” and exporting them to places where they can do more damage because they cannot be monitored.
The academics warned in 2016 that citizenship deprivations encouraged “the dangerous delusion that terrorism is (or can be made into) a foreign threat and problem”.
Sadiq Khan, the mayor of London, said Begum and others should “face the music in Britain”.
“I think if a British citizen commits an offence here or overseas they should face justice in the criminal courts,” he added. “And if [Begum] has committed a criminal offence I’m sure the jury will find her guilty, and justice will be served.”
The Court of Appeal’s judgment has been stayed pending an appeal by the home secretary, meaning that Begum cannot currently gain leave to enter the UK.
Lord Justice Flaux said she could only have a “fair and effective appeal” against citizenship deprivation in Britain, because of an inability to communicate with lawyers from the SDF camp where she is being held.
But the judge added that the ruling did not prevent Begum being arrested upon arrival in the UK and charged with terror offences, or made subject to a Terrorism Prevention and Investigation Measures order.
Sajid Javid, who as home secretary stripped Begum and other Isis members from the UK of their British citizenship, said “difficult decisions” had to be made.
“Limitations in UK law mean there would only be a small chance of significant prosecution for crimes committed in a foreign warzone,” he added.
Richard Walton, the former head of Scotland Yard’s counter-terror command, said Begum’s return would “present a very real challenge” for police.
“She would likely be arrested and charged with terrorism offences but the evidence against her could be weak, owing to the difficulties of obtaining and seizing evidence in warzones,” he added.
“If released, she would present an ongoing threat and would need to be subject to rigorous monitoring costing the state hundreds of thousands of pounds over months and years.”
But Ms Foa accused the government of “abdicating responsibility” for Begum and other Isis members, who were born, raised and radicalised in the UK.
She said: “It’s better to have a justice system that works effectively and to understand and prevent this from happening.”
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