“Isis betreiben Genozid auf Raten” — “Step by step, Isis carries out genocide”. The banner headline in Bild, Germany’s biggest-selling newspaper, appeared on August 15 2014, a few days after Isis took control of the ancient town of Sinjar in northern Iraq. The article beneath it described terrible atrocities — beheadings, enslavement, torture — carried out by Isis militants on members of the Yazidi community in Sinjar and the surrounding villages. Women and girls were being subjected to a systematic programme of rape, some of them as young as eight.

The article was a plea for action, and it worked. Its author was a German psychologist, who had insisted on the word “genocide” as the proper label for the Isis attacks, and because he knew that it would galvanise attention. Within weeks he was at the heart of an unprecedented humanitarian project to bring 1,100 Yazidi women and girls to safety and for medical treatment in Germany. The actions of Jan Kizilhan, an academic who divides his time between the Baden-Württemberg Cooperative State University at Villingen-Schwenningen and a medical clinic in Königsfeld in southern Germany’s Black Forest, were rooted in his own history as a Yazidi Kurd, and in Germany’s own past.

Among the millions of refugees who have fled the advance of Isis in Syria and northern Iraq, the targeting of the Yazidis in 2014 stands out, reflecting an intention to wipe out an entire group. The Yazidis were given an option: convert to Islam or be executed. An estimated 50,000 men, women and children were driven into the mountains around Sinjar and left to starve. Following US air strikes and air drops of humanitarian aid, many of the survivors were escorted by Kurdish Peshmerga troops to camps in Syria, Turkey and northern Iraq. The United Nations has since confirmed that thousands of Yazidi men have been executed, and 7,000 women and girls sold into sexual slavery. Over the past weeks the European Parliament, the US House of Representatives and the Obama administration have characterised the atrocities perpetrated by Isis against Yazidi and other communities in Iraq and Syria as genocide. Other governments, including that of the United Kingdom, have declined to do so.

On a late winter morning, Kizilhan greets me at the entrance to the Michael-Balint Klinik in Königsfeld. Casually dressed, in an open-necked shirt and comfortable shoes, he has the solid air of an academic — understated, steely and intent — with a particularly fine head of thick, deep black and grey hair. “Albert Schweitzer lived here,” is the first thing he tells me, with a wry grin, pointing towards the house built by the Nobel Prize-winning theologian and physician in 1923; home until the Nazis arrived in 1933. Kizilhan’s words offer a connection between the past and the present — humanity then, humanity now — that will continue over the course of our conversations, beginning with the first, in a modest and well-ordered office that looks out on a forest of trees stretching high into the grey sky. He speaks with care, precision and without obvious emotion, as he describes in detail acts as terrible as any I have ever heard. The pain is in his eyes.

Yazidis flee Sinjar in northern Iraq on August 11 2014 © Reuters

“I am 49 years old, a professor and a Kurd,” he offers, as if to simplify the explanation that will follow. He was born in 1966 in a small village on Turkey’s Anatolian plains, a little north of the Syrian border. The second of seven children, he was the son of an illiterate man born into poverty who married a woman from another nearby village. His childhood was a world of Yazidi rituals, memorials for the dead, tales of killings and “genocides” against the Yazidis across the centuries, events known in the local language as “ferman”, a military word from the Ottoman era for a decision that implies extermination.

The Yazidis are a Kurdish-speaking community originating in eastern Turkey, northern Iraq and Iran. They believe in a single god who is good and bad, and their worship of the peacock angel, their most important deity, is one reason Isis describes them as “devil worshippers”. Today’s global Yazidi population is less than a million, most living in northern Iraq. The Turkish Yazidi population of 30,000 half a century ago is down to 500.

Kizilhan’s family knows about death, division and migration. After 1918, when the Ottoman Empire collapsed, most Yazidis fled to Iraq and Syria, while those who remained in Turkey were forced to convert to Islam. His grandfather remained but in hiding, later to be killed by Kurdish Muslims (“because he was Yazidi”, Kizilhan says). Family history is a tale of horrors passed down the generations. He, too, experienced fear, after a military coup in Turkey caused the Kurds to be rounded up and held in March 1971, when he was five. “Soldiers with weapons threatened us in different languages. People who were normally happy and funny were silent. We were told not to speak Kurdish.”

The Yazidis were given an option, convert to Islam or be executed: 50,000 were driven into the mountains and left to starve

By then his mother was working in Germany, near Hanover, and his father followed a year later, in 1972, leaving five-year-old Jan with his grandmother. This was part of a broader migration (the Kurdish Yazidi population in Germany now exceeds 100,000). Jan arrived in 1973, settling with his parents in Celle, near Hanover, in a community of about 20 Yazidi families. “My first experience of electricity,” he says with a smile.

Their neighbours, the Schulzes, were an elderly couple who took the boy under their wing and taught him German. The woman was a teacher, he tells me; they were Jewish and had survived Auschwitz. “The reason I am here and a professor is because of this family, who told me about being in prison for political ideas, because of your different identity.” At school he learnt about the Nazis. “I was 11 when I went to the library and first saw the word ‘genocide’.” He was the only non-Christian in his class; sport offered him protection (“I was the first black belt in karate in Celle,” he says proudly). His was a life of parallel identities, in the tight Yazidi community, speaking Kurdish, and then among his German friends.

His father, who could not read or write, and his mother, who — rare for a Yazidi girl — had gone to school, valued education and urged him in that direction. In 1988 he started medical studies in Bochum. It was also the year that he became politically aware, when Saddam Hussein bombed the Kurdish city of Halabja with chemical weapons, killing thousands of people, many of them Yazidis. After four years he changed courses to psychology. “I wanted to know how the human soul works, how we can influence it, how we can help it to find peace.”

The words reflect a desire to understand how migrants might obtain a sense of home and tranquillity. Kizilhan became interested in trauma, of which he will tell me there are three kinds: historical or trans-generational trauma, in which long-ago atrocities are passed across the generations; individual trauma, abuse felt directly by a person; and collective trauma, one occasioned by abuse dealt upon other members of your community. He grew up in the shadow of a historical trauma, recounted by the “qewal”, the Yazidi storytellers who pass along the community’s oral history. “I became interested in why people were so sad.”

Jan Kizilhan as a boy in the home of his neighbours the Schulzes, near Hanover, where his Yazidi Kurd family migrated after a Turkish military coup in the early 1970s

In 1995, shortly after publishing a psychological study on Kurds in Germany (Der Sturz nach Oben), he went to Washington to take a masters degree in psychology at Georgetown University. This was followed by a stint with the Health and Human Rights Law Project at UCLA — an introduction to traumatised immigrants from Mexico and the wars of Central America — and a year in London and Brussels, working with Med TV, the first-ever Kurdish satellite television station.

There is here a confluence of circumstance, an interplay between his own identity and a nascent intellectual interest in the psychologies of migrant communities. “Migrants would go to doctors,” he says, “but couldn’t explain psychological and other problems.” In Germany, as elsewhere, there was a need to find Turkish, Arabic and Kurdish doctors, recognising the importance of communicating in a patient’s own language. “A person’s psychological state is culturally specific: to solve problems you need to understand the culture, and that means language.”

In 1997 he returned to Germany to complete a doctorate, in Konstanz, on the trauma of migrants, and two years later joined the Michael-Balint Klinik in Königsfeld, where he established a department on migration and transcultural trauma. What began with 10 patients has expanded to hundreds, and over 15 years he has treated more than 10,000 patients, mostly migrants from conflict zones such as Bosnia, Chechnya, Turkey, Rwanda, Iraq and Afghanistan, including many victims of torture and other abuses.

How does he approach the work? “I am a human being, with feelings and emotions. I try to put them to one side, and focus on my expertise. I try to understand, to empathise and talk, but, most importantly, the decision on the path to follow must be made by the patient.” He sees his role as identifying options, setting out possibilities. Over the years a theme has emerged: a patient’s feeling of helplessness, followed by a desire to regain control. Sometimes the victim changes sides and becomes the abuser, “doing as the torturer has done”. He has treated patients who have brought direct accounts from headline conflicts around the world, as well as German soldiers, traumatised by experiences in Afghanistan. By 2014, his knowledge widely recognised, he was often retained by German courts to prepare expert reports, including on terrorism and Islamic radicalisation.

Kizilhan grew up in the shadow of a historical trauma, recounted by Yazidi storytellers. ‘I became interested in why people were so sad’

In August 2014, a dramatic change occurred. Within a few hours of the news that Isis was occupying the Yazidi town of Sinjar and nearby villages, Kizilhan started to receive phone calls from family and friends. “It was a real shock as Isis started to execute.” Can you do anything, he was asked, can you talk with politicians, make them aware? On August 5, at the invitation of a Yazidi intellectual association, he addressed a meeting in Bielefeld in northern Germany, where thousands of Yazidis would march against the Isis attacks. He arrived at a hall filled with “academics and elders, sad and helpless, crying like children”. The intended lecture became a group-therapy session, one with a simple message: “It’s happened before, we will survive, the trauma and the genocide will make us stronger.” His focus was clear: “It’s a ferman, a ‘genocide’, we cannot stop it ourselves, we need help from outside.” He knew the word “genocide” centred on the destruction of a group, not merely the killing of individuals, even in large numbers.

What was the effect on you? I ask. “I am educated in Germany,” he says, “so I stay cool.” He laughs at himself. He wanted a logical approach, “to fight, not stay at home and do nothing, as my ancestors did”. So he wrote to politicians and to the editors of Bild, a paper that doesn’t often reflect his views but is widely read in Germany. After the article was published, a second community meeting followed, drawing more than 600 Yazidis from across Germany. No witnesses were present from Sinjar to give first-hand accounts of the genocide, so they relied on reports received by phone, via the internet and in photographs.

German politicians were piqued into action, at state and federal levels, up to Angela Merkel’s office. “Even the intelligence services of different countries wanted to know who the Yazidis were,” he says. Ever-more graphic accounts emerged, including videos and photographs of beheadings and executions, and the abuse of young children. The minister-president of Baden-Württemberg, Winfried Kretschmann, of the Alliance ’90/Greens party, became involved. “An expression of humanity, not politics,” Kizilhan says. The state’s regional parliament resolved to help, and an urgent programme was established to bring traumatised Yazidi women and girls to Germany. Kizilhan was appointed medical and psychological head of Baden-Württemberg’s Special-Quota Project to bring 1,000 Yazidi women from refugee camps in northern Iraq back for treatment.

Yazidi families take refuge in an abandoned building near Dohuk, August 25 2014 © Reuters

In February 2015 he travelled to northern Iraq and visited several camps around the city of Dohuk, run by the Kurdistan Regional Government in Iraq or the UN, each with about 20,000 refugees, including many who had escaped from Isis captivity. Kizilhan spent two weeks there and over the course of the next year made a total of 14 visits. For him it was the most testing of experiences: he examined many women and girls to decide who would travel to Germany and who would stay behind. His team had a long list of names — women and girls who had been enslaved, raped and tortured, and then escaped. Three basic criteria were adopted to guide the selection process. Had the woman or girl escaped from Isis captivity? Was there clear evidence of severe abuse and psychological consequences from the period of captivity? Would treatment in Germany help, beyond what was available locally?

“We had few plans or ideas, basically just a decision to bring 1,000 people to Germany, and a budget of €95m,” Kizilhan explains. He interviewed 1,403 women and girls, many of whom were deeply traumatised. He had time for an initial examination, usually about 30 minutes, but occasionally up to two hours. The decisions were taken with two other colleagues (Michael Blume, who leads the Baden-Württemberg project, and an adviser from the German visa office) and sometimes involving one or more Iraqi doctors. Each decision would change the life of an individual, and each turned on its own particular facts.

“Still now I don’t really want to think about it,” he says. “It was hell to make such decisions, to decide for that one, yes, you meet the criteria, but for another one, no, you do not.” The elderly, or girls who were alone, would not be selected, the former because it was felt they would not benefit from a programme of treatment, the latter because they should not travel without close family members. “There was one child, she was nine or 10, we decided she could not come alone but then, after two months, an aunt was freed from IS [Isis] and we agreed to bring them both.”

It was hell to make such decisions, to decide for that one, yes, you meet the criteria, but for another one, no, you do not

There is more to do, as many women have been left behind, and he continues to work with governments and aid organisations to get them out. “There are Yazidi communities in France and in England who could be involved, with help,” he says. What does he need most? “Psychologists experienced in trauma, and translators,” he says. “We would be happy with English psychologists, as we can train the translators and social workers.”

The stories he tells are beyond distressing, in detail and range. “The youngest person I examined was eight years old. She was taken with her mother, first to Mosul then to Raqqa. She was sold eight times, raped more than 100 times over a period of 14 months.” Kizilhan looks at my face, seeing my obvious reaction, but still he asks: “Can you imagine what it means for this girl? That case was clear, she came because otherwise she would not survive.”

In one camp he was taken to a 16-year-old girl. “She opened the tent, I was shocked. She was like a zombie. She was two weeks in the hands of IS, then escaped. During this time, they raped her sister. She had nightmares that IS was outside her tent, so she decided the only way to avoid being raped was to make herself ugly. She took a canister of oil and poured it over herself. She burned 80 per cent of her body.” He arranged for her to be airlifted from Erbil to Germany, where she has had 12 operations. She is recovering, he says, sort of. “When I asked her what she would like most, she said she’d like to be able to walk down a street, sit in a café, have an ice-cream, without anyone staring at her.”

The responsibility weighs heavily on him, having tried to act fairly, “like an angel or God”. He says drily: “It’s not a huge programme but at least we rescued 1,100 lives.” The majority of the women and girls are in Baden-Württemberg, except for 70 in Lower Saxony and 30 in Schleswig-Holstein, with strong local support. The youngest is eight, the oldest 55. The average age is about 19. “There are 3,800 Yazidi women still being held by IS,” he says, “and maybe another 3,000 missing.” There are also 1,000 Yazidi children who have been taken and are being trained as child soldiers, being turned against their own mothers. “That is what I mean by a collective trauma,” he says.

Jan Kizilhan meets Yazidi women at Khanike refugee camp in northern Iraq, October 2015

I ask about patterns of mistreatment. The abuse is systematic, a programme. “IS works to a plan,” he says. “They come to the villages, collect people in schools, take money and valuables, then start to execute the males.” Older women were separated from the young. “Women with children were taken to one place; the unmarried and, especially, virgin girls, to another. There they are repeatedly raped and then sold on. Children between eight and 14 years are taken for training in Islam and turned into child soldiers. The children go to Mosul, are collected at the Galaxy cinema, and guys come from all over. It’s like a slave market: you look at the girls, buy them, take them away.” The reference to the cinema is repeated in many accounts, along with other details: “The most brutal IS fighters are said to be the foreigners who’ve converted to Islam, those who came from abroad, from Germany, England, Australia.” How do women and girls know this? “The foreigners speak poor Arabic, and they use alcohol and drugs.”

This is violence with a purpose, not random or mindless. Rape is used as an instrument of transformation, to turn a Yazidi woman or girl into a Muslim, making it difficult for victims to feel they could ever again be fully integrated into the Yazidi community (Kizilhan tells me that a significant number have committed suicide). Isis is “a fascist Islamic organisation,” he says, one that has decided that those unwilling to convert to Islam are not human and have no right to live.

The women and girls who have come to Germany are placed into groups of about 20. Kizilhan treats a number of them, seeing them individually once a week, with additional group sessions. He tells me about a 26-year-old woman with two children, aged five and six. When she was captured by Isis she had three children. Twenty-one men from her family were executed in front of them, including her husband and her father. “She was sold many times and raped, lastly by a foreign fighter, a man called Abu Jihat,” Kizilhan explains. He forced her to learn the Koran but, as a Kurdish speaker, her Arabic was not good, so she was punished. He took her two-year-old daughter, called Tuli, and placed her in a tin box in the courtyard, where she stayed for seven days. This was Raqqa, in August, in the heat. Abu Jihat says to the mother: ‘If you take her out, I will [kill] the other two children.’” Tuli is taken out after seven days. Abu Jihat submerges her in ice-cold water, beats her, breaks her back. She lives for two more days, then she dies. “This is how the unbelievers will be treated,” the mother is told.

The psychological question that I try to understand is: how can people do that? They are using the same techniques as the Nazis

Kizilhan recounts the story in a dull, flat monotone. He has trouble processing such acts of individual horror and inhumanity, as do I. “The psychological question that I try to understand,” he says, “is: how can people do that?” He reaches for an obvious parallel. In his understanding, a psychological conversion has taken place, one that “allows IS to believe that Yazidis, Christians or Mandak or Shabaks, the minorities, are not actually humans”. He pauses. “They are using the same techniques as the Nazis.”

What kind of a future can Tuli’s mother expect? She will stay in Germany, and her best prospect is her two remaining children. “They are young, they will be OK, they don’t want to go back, they will all stay.” But that’s not enough, he adds. They need a sense of justice, an attachment to hope. Tuli’s mother wants the world to know what happened to her daughter, and she wants Abu Jihat to be punished.

Kizilhan sees a connection between the possibility of justice and the future wellbeing of victims. Characterising such atrocities as a genocide is a first step, and he welcomes the use of the word by the European Parliament and the Obama administration. “Calling it a genocide,” he says, “recognises the group’s identity, what is being done to it, and its right to exist.”

The crimes are being investigated by German prosecutors, and he urges international action. “One part of identity is about not forgetting,” he says. “The law can help, a way of dealing with past wrongs and present traumas, reinforcing memory.”

Our conversation drifts to the Nuremberg trials and Germany’s own history. Kizilhan recognises the outpouring of help offered by the community in Königsfeld and elsewhere, hundreds of volunteers getting involved, many from the older generation. “They came to my public lectures and they say to me, ‘Yes, we know about these things, from our own past.’”

Kizilhan: the solid air of an academic, steely and intent © Andri Pol

Kizilhan invites me to meet briefly with a number of the women and girls, and one boy. The youngest is two, the oldest in her late twenties. One girl, 13-years-old, speaks a little English. Another, a bit older, wears an improbable black T-shirt emblazoned with the words “I [lips] Boys”. I share small gifts that I have brought for the children, chosen with help from Kizilhan. Tea is served in glasses as we gather around two large red sofas, 12 of us: Kizilhan, me and 10 recent escapees from Isis. Some stand, others sit, holding hands. The two-year-old falls asleep in her mother’s lap. There is a profound sense of togetherness in this small, tight group, an uncertain and melancholy air but, intermittently, smiles and moments of loud laughter (“I am not interested in English football,” the 15-year-old boy tells us, “just Barcelona.”).

It is difficult to know what to say in the humbling presence of a group of women and girls who have been sold and enslaved, tortured and raped. Kizilhan encourages me to talk, to express solidarity and to ask questions. I avoid asking about individual traumas, but the collective trauma sneaks its way in when I ask about those who remain in northern Iraq. “We don’t know where they are, we have heard nothing.” As these words are spoken one of the mothers looks away from me, eye contact impossible at that moment (Kizilhan has told me that some women have been “disappeared” to other countries, including Pakistan, Afghanistan and Saudi Arabia).

What is to be done? A young woman, about 17-years-old, intervenes. She has been observing our conversation, and I have noticed in her demeanour and in her eyes a fighting determination. “My sister and brother were beheaded in my presence,” she says forcefully. “What is to be done? Daesh [Isis] has to be destroyed, that is what is to be is done.”

She shows no fear, this young woman. As we leave, Kizilhan’s words at the community meeting, when the horrors began, come to my mind. “It’s happened before, we will survive; the trauma and the genocide will make us stronger.”

Philippe Sands is professor of law at University College London and a barrister at Matrix Chambers. @philippesands

His new book ‘East West Street: On the Origins of Genocide and Crimes against Humanity’ is published on May 24 by Alfred Knopf (US) and Weidenfeld & Nicolson (UK). A film based on this article is being made by Oxford Films and BBC Storyville

Photographs: Andri Pol; Reuters