The handwritten letters addressed to Kheda Saratova often begin with the words: “I’m asking you to find my daughter.”

The Chechen human rights advocate has binders filled with photographs of young women and children, as well as their last known locations: Mosul, towns near Raqqa, or sometimes just “tent camp”.

Then there are the pleas for help sent over WhatsApp. “We aren’t dangerous,” wrote Maria, a Russian in the Ain Issa refugee camp in Syria. “Maybe there are some who are dangerous, but we should not all be punished for them.”

Altogether, family members have appealed to Saratova to find at least 1,800 Russian-speakers who have disappeared into Iraq and Syria, many of whom arrived in the two countries to live under Isis. “We need to hurry or there won’t be anyone left to return,” she said.

Women like them have been dubbed “Isis brides” in the west, and their possible return has sparked a fiery public debate, with governments taking unprecedented steps to block their repatriation.

Shamima Begum, the teenager who traveled from east London to Syria in 2015, had her British citizenship revoked. The United States made a similar decision to block the return of Hoda Muthana, an Alabama woman.

Russia has a far larger problem. Vladimir Putin has claimed as many as 4,000 Russian citizens traveled to Syria and Iraq, and another 5,000 from other ex-Soviet countries. Saratova says relatives are seeking at least 700 women from countries such as Russia, Kazakhstan, and Uzbekistan, and more than 1,100 children.

The campaign for their return has found an unlikely champion in Ramzan Kadyrov, the strongman ruler of Chechnya, whose regime has long been accused of brutal reprisals against Islamist insurgents and their families.

However, Kadyrov has lobbied Vladimir Putin for the return of Russian-speakers from Isis and helped organise nearly a dozen evacuation flights from Syria to Grozny, the predominately Muslim capital of Chechnya.

Kadyrov has lobbied Vladimir Putin for the return of Russian-speakers from Isis. Photograph: Dmitry Astakhov/AFP/Getty Images

Observers suggest that he has various motivations: keeping potential insurgents under watch, promoting his stature as a Muslim leader, and a genuine belief, coloured by a patriarchal worldview, that the women who emigrated were bound to follow their husbands into Isis.

“From the humanitarian point of view, this is a very strong and quite unexpected position,” said Ekaterina Sokirianskaya, the director of the Conflict Analysis and Prevention centre and an expert on the north Caucasus.

Supporters of the scheme, which brought back 21 women and more than 100 children in 2017, claimed that repatriating those who had lived under Isis would help keep the country safer.

“These people need to be brought back, so that they’re under the control of our law enforcement agencies,” said Saratova, who was appointed by Kadyrov to a committee that manages the repatriation process.“They are more dangerous there than here.”

But the scheme has its opponents and was suspended abruptly in 2017 after complaints from senior officials in Russia’s security services. Evacuations of children resumed only in December 2018. Women are no longer repatriated.

Chechen human rights advocate Kheda Saratova. Photograph: Andrew Roth/The Guardian

Zalina Gabibulayeva, a mother of five who now lives in Grozny, was on the last flight out of Syria. She seemed an unlikely candidate for clemency. Her first husband had fought in the insurgency in Dagestan and was killed in 2010. In 2012, she was sentenced to two years in prison after police found a bomb in the trunk of her car, which she said was planted.

While the Chechen government has portrayed the women it wants to repatriate from Syria as obedient wives, each case is unique. Gabibulayeva said that she was single and made her own decision when she slipped across the Turkish border in 2014. “I had religious motivations,” she said during an interview in Grozny. “I thought it was sharia. I wanted sharia.”

Gabibulayeva settled in Tabqa, a city she called “peaceful” at first but she said she soon grew disappointed with Isis’s strict rules, wanton use of violence and the cost of the approaching war. “At first, there were more good people than bad,” she said. “They killed them like cannon fodder, sending them to die in this war.” Executions for legal violations were also common, she said. She denied taking part in violence.

Single women were confined to a general barracks and not let out alone, so she quickly married, she said. Her third husband was killed in a drone strike less than a year after they wed. As the war drew closer and aerial bombardments became more frequent, she and her fourth husband, a Macedonian, decided it was time to leave.

They paid to be smuggled out of Isis territory in mid-2017 and surrendered to Kurdish forces in the country’s north. Gabibulayeva, who was pregnant with her fifth child a the time, gave birth in al-Hawl refugee camp. “They didn’t even bring me to the hospital, though I asked them,” she said.

Her husband was arrested and extradited to Macedonia, where he is now in prison. She spent four months in camps before she was suddenly flown back to Russia, where a court in Dagestan convicted her of joining an illegally armed group. She was sentenced to prison, but given a deferment of more than a decade because she has young children.

She considers herself lucky to have got out alive. “When the war was at its peak, when the children were between life and death, of course you choose prison over the death of your kids,” she said.

Gabibulayeva and another returnee, Zagidat Abakarova, a mother of four, said that they had been subjected to intense scrutiny after returning to Russia, with regular interrogations and police visits in her native Dagestan. She moved to Chechnya, she said, because government forces had been more lenient. Russia has no federal guidelines for repatriation, and each region has dealt with returnees in its own way.

She assumed that their phones and other means of communications were being monitored, but said that women who had lived under Isis no longer posed a threat.

Not everyone agrees. In November, Alexander Bortnikov, head of Russia’s federal security service, said that brining women back was dangerous: “It’s no secret that these women and even children are used by terrorist leaders as recruiters, suicide attackers, for perpetrating terrorist attacks and as gobetweens.”

Putin has also spoken publicly in support of repatriating children, although he has not addressed the question of women. Evacuation flights from Syria suddenly resumed for children born in Russia late last year, with 30 children evacuated in December and more.

Observers say that Russia’s approach is flawed but has shown more readiness to repatriate those who left for Isis than any western government.

“Russia has one of the most active programmes on repatriation of children globally and should be given credit for it,” Tanya Lokshina, of Human Rights Watch, said. But “given all that hope to the families desperate to get daughters and grandkids back from Syria and Iraq – and then suspending the original programme for a year without any explanations, it was a huge and unjustified blow to those families.”

Some mothers still have hope their daughters will be found alive. Dzhannet Erezhebova has been searching for her daughter Ziyaret for more than two years.

“If I disappear, please don’t leave my children here, find them,” Ziyaret texted from Mosul in November 2016, where she was living in a barracks for widows with her three children. Her husband had already died in a bombardment.

It was the last time time that mother and daughter spoke, and Erezhebova has spent more than two years searching for clues that her daughter and three children escaped the city.

“I have been burying her and bringing her back to life all this time,” Erezhebova said . “She deserves another chance.