Shamima Begum has lost her challenge over the decision to deprive her of British citizenship despite a credible case she was trafficked.
Mr Justice Jay told the semi-secret court dealing with her case that her appeal had been fully dismissed.
The decision means the 23-year-old remains barred from returning to the UK and stuck in a camp in northern Syria.
Ms Begum was 15 years old when she travelled to join the self-styled Islamic State group in 2015.
She went on to have three children, all of whom have died, after marrying a fighter with the group.
In 2019, the then home secretary Sajid Javid stripped her of her British citizenship, preventing her coming home, and leaving her detained as an IS supporter in a camp.
The Special Immigration Appeals Commission has ruled that decision, taken after ministers received national security advice about Ms Begum’s threat to the UK, had been lawful – even though her lawyers had presented strong arguments she was a victim.
The Shamima Begum Story
During the appeal hearing last November, Ms Begum’s lawyers argued the decision had been unlawful because the home secretary had failed to consider whether she had been a victim of child trafficking – in effect arguing she had been groomed and tricked into joining the fighters, along with school friends.
In a summary of the ruling, Mr Justice Jay said: “The Commission concluded that there was a credible suspicion that Ms Begum had been trafficked to Syria.
“The motive for bringing her to Syria was sexual exploitation to which, as a child, she could not give a valid consent.
“The Commission also concluded that there were arguable breaches of duty on the part of various State bodies in permitting Ms Begum to leave the country as she did and eventually cross the border from Turkey into Syria.”
But despite those concerns, the judge said even if Ms Begum had been trafficked, that did not trump the home secretary’s legal duty to make a national security decision to strip her of her British nationality.
“There is some merit in the argument that those advising the secretary of state see this as a black and white issue, when many would say that there are shades of grey,” said the judge in his summary.
But despite those questions over how the case had been handled, the Commission concluded the home secretary had still acted within his powers – even if there could have been a different outcome.
“If asked to evaluate all the circumstances of Ms Begum’s case, reasonable people with knowledge of all the relevant evidence will differ, in particular in relation to the issue of the extent to which her travel to Syria was voluntary and the weight to be given to that factor in the context of all others,” said the judge.
“Likewise, reasonable people will differ as to the threat she posed in February 2019 to the national security of the United Kingdom, and as to how that threat should be balanced against all countervailing considerations.
“However, under our constitutional settlement these sensitive issues are for the secretary of state to evaluate and not for the Commission.”
It’s not clear yet whether Ms Begum will appeal – but a spokesman for the Home Office said it was “pleased” with the outcome.
“The government’s priority remains maintaining the safety and security of the UK and we will robustly defend any decision made in doing so,” said the spokesman.