After a long day patrolling the Isis border with a Kalashnikov, what the young jihadi fighter looks forward to is getting back to the ‘women’s guesthouses’ for a shower and a one-night ‘pleasure marriage.’

If he happens to bring a loaf of bread or a bar of chocolate, skinny-ribbed girls will line up to be blessed by an imam before climbing into the bridal bed. The marriage will last a couple of hours and be annulled in the morning so the woman can be passed on to someone else.

This is just one of the many stories I heard from the 70 or so women, children and disaffected fighters I helped to rescue from the so-called Islamic State, over three years.

The religious one-night-stand, if you will, tells so much about its twisted morality: religious piety is key, and sex outside of marriage is forbidden, yet jihadi fighters could sleep with dozens of women – be they locals, European converts or Yazidi slave girls – all while preaching purity.

From 2014 until the collapse of the self-declared Islamic Caliphate in March 2019, thousands of young women made the unconscionable decision to leave their families and travel in secret across Europe to Iraq and Syria.

Under the spell of Isis lies and propaganda, they went for the promise of love, adventure and jannah – the paradise on earth predicted in the Quran. What they found was a living hell.

In the scores of interviews I conducted, I heard how girls as young as 15 were sold in Isis slave markets to drug-fuelled jihadis boasting how they intended to score their 72 virgins on earth rather than wait for martyrdom. Raped, starved and beaten with canes, most had watched beheadings. One girl caught with a mobile phone was stoned to death and her sister brides had to join, in terror.

Why did they go – and why did I end up trying to get them out?

John Carney has spent the past three years rescuing women and children from Isis territory credit: AP

Some background. After a dismal start – a violent father, low self-esteem – life had been good to me. I served six years in the Yorkshire Regiment and did two tours of Northern Ireland. I went to Iraq in 2003 and climbed the greasy pole to team leader with Aegis Defence Services, the private security firm set up by Colonel Tim Spicer.

When US and British forces pulled out of Iraq, Saddam dead, job done, it left a gap in the security market. I stayed on and formed a close protection business, escorting oil men and TV crews out of Baghdad’s Green Zone into the badlands of the Wild East.

My drivers were mainly Iraqi, many of them Kurds. I picked up street Arabic, learned the intricacies of baksheesh – the tipping, or bribery essential to survive – and built an extensive network of contacts.

It was through one of these contacts that the family of Laura Angela Hansen, a Dutch girl aged 21, begged me to rescue their daughter and the two children she had with her violent Isis husband, who she said had tricked her into travelling to Iraq in 2015.

She was now stuck in Mosul, where Assyrian masons laid the first mud bricks 2,000 years before Christ; now an Isis stronghold of narrow streets and secret tunnels.

That hot summer, Mosul was being bombed to dust by US-led Coalition air strikes, but was still ringed by land mines and jihadi gunmen in Ray Bans and black turbans.

Extracting Laura, I knew, would be a suicide mission. But she had managed to get word to her parents that she was being abused; when they showed me a picture of her as a three year-old in pyjamas, she looked just like my own daughter had at that age.

I agreed to arrange her escape with three Kurds, ex-military men with big shoulders, few words and, like me, daughters of their own, but Kurdish Peshmerga forces swooped and scooped her up first.

Still, when news of her escape reached the Muslim community, my inbox began to ping like a pinball machine with emails from families in London, Amsterdam, Paris, Munich. They all had the same message: “Please, Mr Carney, please bring my daughter home.”

From that morning in July 2016 until the last days of Islamic State, we ran a non-stop mission we called 'Operation Jihadi Bride', bringing women and their children to a place where they could hand themselves over to local security services.

Unlike Shamima Begum, most of the 70 women Carney rescued, felt remorse about their decision to join the Caliphate credit: Sam Tarling

We arranged the place to meet ahead of time on encrypted chat apps, such as Telegram or WhatsApp. Meeting near hospitals was common, because young women and children would always have a reason to be travelling there.

We followed the Peshmerga as they advanced into Mosul, Raqqa, Deir-ez-Zur. As cities erupted in street fighting, women we had set out to extract ran over the rubble, shedding their black abayas and being shot at by snipers. I will never forget seeing a small boy’s head exploding like a watermelon, and the look of terror on the face of his traumatised mother.

We took local women to refugee camps on the Turkish-Syrian border, which I watched grow from a few hundred thousand to three million people.

We took the European girls back to one of the safe houses we had rented from locals to be de-briefed of their valuable testimony. They were able to confirm intel from our informers on arms caches and secret tunnels that allowed jihadi commanders to escape to Turkey with suitcases full of cash; information I fed to MI6 and Asayish, the Kurdish secret service. In turn, the Isis recruits could bargain for freedom.

Islamic State propaganda videos showed happy children in schools, men and women working freely in corn fields, female engineers building bridges and running sophisticated medical clinics. The truth was shocking and sordid: a generation of young men brought up on internet porn had been sanctioned by Isis to turn vast swathes of Iraq and Syria into a giant brothel ruled by the gun.

Some of the girls had been ‘lucky’, married a jihadi fighter and remained his partner. Those who had been widowed, or whose partner had been posted to another war zone, were bought and sold, like slaves in a market, to the highest bidder.

Shops selling ‘new-look’ burqas, head to toe black gowns with narrow eye slits, also sold the sexiest underwear in the world, tiny panties and push-up bras.

‘They like us to keep our hair long and remove every trace of body hair,’ Diana Abbasi* one of the English girls told me. ‘When they peel away our clothes they want to find children dressed as porn stars.’

‘If a man has food and comes to our building, all the girls will offer to sleep with him,’ another girl told us. ‘We were prostitutes for food.’

Thousands of women and children have been left stateless following the collapse of the Islamic State, including Begum, pictured here leaving the UK credit: AFP

Marriage in Islam is halal – holy. Sex outside marriage is haram – blasphemy. But hormones being what they are, and young men being what they are, Sharia Law provides a safety valve called mut’ah, a pleasure marriage.

Mut’ah marriages came about when men travelled long distances by camel or on foot to trade or during pilgrimages to holy sites. Men were not expected to go without their comforts and in guesthouses a one night marriage was standard practice.

The woman says to the dusty new arrival: ‘I marry you, myself.’ To which the man replies, ‘I accept.’ The husband for the night provides a money gift and some sweet delicacy. Divorce is granted automatically after fajr, the dawn prayer.

Though Shamima Begum – the jihadi bride who left London aged 15, and is now stateless in the rat-infested refugee camp of al-Roj – has expressed remorse for no one but herself, many of the women we rescued expressed deep regret.

“I made a mistake joining Islamic State. I knew it the day I arrived,” Abbasi told me. Unlike Begum, she was allowed to return to the UK, went through a Prevent deradicalisation course and is now a counsellor in the same programme.

Thousands more Jihadi brides and children are still living in camps in countries that don’t want them. The UK doesn't want them either. The Netherlands has a more liberal policy: Laura Angela Hansen was given a suspended sentence for planning to prepare and promote terrorist activities, but acquitted of belonging to Isis, and her children are back living with her in Amsterdam.

The German government is repatriating children from refugee camps with the consent of mothers, left behind. One 27 year-old woman known as Jennifer W is currently on trial in Munich, accused of allowing a five year-old captive Yazidi girl to die of thirst, while she was chained up in 45-degree heat as a punishment for wetting the bed.

In a recent policy change, the French have concluded that it is better to bring their jihadi brides back to face “the full weight of the law,” than allow them to scatter and regroup to plan atrocities in Europe.

Islamic State with its torture, brutality and evil hypocrisy may no longer exist as a territorial power, but it will rise again and we in the West must be vigilant.

As told to Clifford Thurlow

*Names have been changed

Operation Jihadi Bride by John Carney with Clifford Thurlow is published by Monoray (RRP £18.99). Buy now for £16.99 at books.telegraph.co.uk or call 0844 871 1514