That relationship began for Seierstad two weeks after 9/11, when, as a freelance foreign correspondent, she embedded herself with the Northern Alliance of forces that, with western support, would sweep the Islamic fundamentalist regime from power. Twenty years later, she has been among the few journalists to go back after the desperate airlift that ended US and British support for democratic government and to spend time bearing witness to the Taliban’s chilling return to power.

Her history is bookended by two intimate reports of the lives of families living through those decades of conflict and fear. The first, The Bookseller of Kabul, became a bestseller around the world. That book was more than just a literary sensation, however. It became – after the bookseller on whom the book was based sued Seierstad in Norway for defamation and invasion of privacy – a decade-long test case for all sorts of things: not least of the rights of writers to use other people’s lives as material. Her second book, The Afghans, to be published this month, is a kind of sequel (“More a stepbrother or a cousin,” she says) to that first book. Through three separate, intimate portraits, it offers a window on the present moment in Kabul, a clear-eyed and sometimes heartbreaking account of a city that has lately been pushed from the front pages, but remains a defining fault line in the world.

The thread between the two books is Seierstad’s determination to have the reader see that recent history, in particular, through the eyes of women in Kabul. Her legal problems with the bookseller were rooted in that determination. Shah Muhammad Rais (called Sultan Khan in the book) welcomed Seierstad into his family and his home for many months in 2002 after agreeing to her idea of a book. No doubt he believed the story would tell the world of his undoubted heroism in keeping open for almost 30 years a wide-ranging bookshop at the heart of one of the world’s most devastated cities, despite imprisonment and censorship and sprees of book-burning by communist and Taliban forces.

Seierstad’s book did tell exactly that courageous story, but it was also an honest account of the patriarchal tyrannies of Khan’s world. At the time of the book, Rais was, “according to custom”, and to the anguish of his first wife and children, taking a second bride, 16 years old. Seierstad’s book did not judge that behaviour, but did not flinch either from examining all its emotional impact, telling it like it was. As Seierstad makes clear, the struggle she was describing was not just a war between Afghanistan and the west, or between strict Islam and liberalism, but most critically, on a day-to-day level, between draconian traditions of male power and Afghan women’s hopes for education and choice.

Seierstad, 54, had not, she says – the court cases aside – really kept closely in touch with Afghanistan in the years since. Her other books include The Angel of Grozny, an on-the-ground account of Chechnya under Russian occupation, and One of Us: The Story of Anders Breivik and the Massacre in Norway, a raw eyewitness telling of the devastating 2011 terror attack in her home country, which became the basis for the Netflix drama 22 July. She had been working on other projects when she watched on the news the events of August 2021 in Kabul as the Taliban returned; she felt she had no option but to go back.

The trigger for her book was a woman she calls Jamila. Seierstad heard Jamila speaking at a livestream debate in Norway – where she was seeking asylum – on the future of her home country. “Hers was such an interesting voice,” Seierstad recalls. “So western when it comes to human rights, but so grounded in her own culture in other ways.” Jamila was born in 1976 and had lived through enough history for several lifetimes. Her life was one of cheerful defiance: first, towards the polio that debilitated her as a child, then towards attitudes that said that, unlike her brothers, she should stay at home, not go to school, and hope that a husband might take her on. Jamila was having none of that. She not only got an education, she was instrumental in an organisation promoting the teaching of women and girls. All these efforts had been brutally undone by regime change.

Seierstad pieces together Jamila’s extraordinary life story in the context of her present situation – including the hostility to refugees in some inevitably political quarters (the rightwing Progress party, Norway’s version of Ukip, remains an electoral force in the country). The pair first met in an asylum centre an hour from Oslo, then up in a fishing village on the frigid northern coast called Alta to which Jamila has been incongruously relocated. “The problem is, with her disability, Jamila can’t walk on ice, so she was stuck indoors again. The whole policy when these Afghan women first came here was: ‘Oh, we’re going to help them form networks and solidarity.’ But how can we do that if they’re all isolated in different fishing villages?”

Seierstad’s ambition as a writer is always to bring the individual fully to life, giving a human truth to war, in the tradition of Martha Gellhorn or Svetlana Alexievich. For Jamila’s story to work in a book, she realised she also had to put a face to her adversary.

She flew to Kabul in 2022. She was lucky, she says. “I got to the ministry of foreign affairs at the same time as John Simpson. I think he was invited to meet the vice-foreign minister and I kind of snuck in.” Fluent in five languages, Seierstad had once imagined that she might be a diplomat; journalism was the next best thing. “I told the minister,” she says, “that I was looking for a high-level Taliban commander to speak to for this book. And he laughed and said: ‘No one’s going be in your book. We don’t talk in our movement.’”

The regime was still trying to put a more moderate face to the world, however, so the minister granted Seierstad permission to try. Was The Bookseller of Kabul mentioned, I wonder? “I always mentioned it,” she says. “But of course the Taliban don’t read secular books – and they had plenty of other things to worry about.”

Through a fixer whose brother was Taliban, Seierstad toured police stations and military camps looking for a suitable subject. One day her fixer found a man she calls Bashir, who was living in some style in a huge gated villa, commandeered after the US forces left. Bashir had grown up to avenge the martyrdom of his father, a mullah, executed by security forces when he was a boy. His family subsequently had one thought: Bashir’s happiness. And one goal: jihad. By 16, Bashir was planting bombs himself; at 20 he was a precocious guerrilla commander ambushing American troop convoys. With the return to power, Bashir had created for himself a role as a troubleshooter and magistrate in the upper reaches of Taliban authority, delivering ad hoc judgments around the city.

For reasons of his own – “I guess status” – Bashir invites Seierstad to observe his life and that of his wives. The openness reflects a swagger in Taliban authority. “If I’d come last year, you’d have kidnapped me,” Seierstad says; Bashir laughs and agrees.

Again, in balance with her account of Jamila’s life, Seierstad builds a picture of the day to day domestic reality within the Taliban over the following months. “In some ways,” she says, “the visiting female reporter has special access, because you are also able to talk to wives and daughters.” She was, she says, more wary than she had been 20 years ago, not so much of the Taliban, but of the growing Islamic State faction in the city. Her stock question to Bashir, and those she met, she says, was that ever-useful sports reporters’ line: “And what was going through your head at that moment?”

Bashir’s mother and wives, having lived lives of rural poverty and hardship, were enjoying the spoils of victory in the city: “But they were also kind of bored after all the struggle, stuck now in the big house.” Hardly allowed outside, the women had time to talk to Seierstad.

I wonder how much they asked questions of her own way of life? “Not so much,” she says. “They had heard that women go around naked in Norway. I tried to explain the concept of what is taboo to show and what is not.” She gestured to a skirt length above the knee and the women winced. When she told them she had travelled alone, they asked: “How come your family doesn’t love you?” Questions about marriage – Seierstad is divorced, while some of the Taliban wives were pledged to their husbands for life as babies – prompted a great deal of misplaced anguish.

Those women’s lives are not the only ones in Kabul, of course. For 20 years, since her last visit, the coalition-backed government had promoted the education of women. The third strand of Seierstad’s book involves a young woman she calls Ariana, who had taken advantage of those reforms. Ariana’s life is now torn in half between the forces represented by Jamila and Bashir. She had been an A-grade student throughout school and was in the last term of a law degree when the regime changed (specifically, she was in her room working and listening to Justin Bieber when the awful news came that the Taliban had returned to the city).

Since then, Ariana’s freedoms have been curtailed one by one. Seierstad tells the story of Ariana’s attempts to return to her university campus, only to be ordered home because “the boys are back now”. Her parents lived in fear of reprisals for having worked with the previous government; they insist that Ariana’s only future is the old, discredited one – an arranged marriage and forget any ideas of law. Seierstad relates the hopeless reality of this loss of freedom with heartfelt detail. She remains in touch with Ariana and has used some of the funds from her book to help her to buy a flat.

“It is worse now than when I was there,” she says, with the ban on girls’ education extended to all girls over 11. “Ariana sent me a video of her beautiful little sister,” she says. “Very bright and intelligent and cute. It was her last day at school. And she’s crying and saying: ‘I just want to keep going.’ And of course the girls have nothing else. It’s not like they do ballet or horse riding. Once they can’t go to school, they also can’t leave their house.”

Seierstad makes a point in the book of saying how hard she tries to always keep to the perspective of the person telling the story. I wonder how easy it was to switch off her judgment around Bashir and the Taliban? “Well, it’s not really so difficult,” she says. “I mean, I wrote the book on Anders Breivik, too, you know. And even with him, I was thinking: ‘How is this possible? Where do these ideas come from?’”

The trick is maximum empathy, she says: “But it’s also a bit, I think: ‘The army should get to know their enemy better than they do.’ If we had known the Taliban better as individual people, is there a way that we could avoid them taking full power?”

A few of Seierstad’s methods have changed since The Bookseller of Kabul; for one thing, she says, she tapes absolutely everything now rather than taking notes, as before. She is no doubt a little more scarred by that legal process than she allows. After the legal case, there has not been a way to resume contact with Rais.

“People asked me when I went to Afghanistan again: ‘Is this a follow-up story?’ And I was like: ‘No, no, it’s nothing to do with the bookseller.’ I wanted to put all that behind me. In the six months I was there, this time, I didn’t even go to the bookshop. But then the very last night I was there, I woke up at four in the morning and thought: ‘I have to go.’ That morning, I went with Ariana.”

What did she find there? “I went up the stairs to the shop, totally covered with my headscarf. And as I got to the top, this young guy was saying: ‘Are you Åsne?’ He was the bookseller’s nephew. He had been eight years old when I lived there, but he must have remembered me. He took a photo to put on Instagram: ‘The author is back!’”

And was he selling The Bookseller of Kabul? “Yes. It was there on the counter.”

That promise of a circle closing in this story, however, was short-lived. News of the bookshop since Seierstad’s visit has not been so good. In December last year, the Taliban reportedly arrived, locked the doors and ordered the employees to hand over all the passwords for Rais’s website, destroying the catalogue he had built up since 1974. Refusing to be defeated and now in London, Rais is, the Guardian reported last month, rebuilding his archive of Afghan books remotely, with titles being printed on pdfs and sent to fulfil orders in Kabul.

The facts prove Seierstad’s understanding that there are still no happy endings in Kabul, only gestures of despair and struggle. If The Bookseller of Kabul continues to offer one enduring example of that continuing tragedy, her new book presents another.