When Charlotte Delbo – a French dramatist arrested by the Germans in Paris and sent to Auschwitz in 1943 – came home from the camps, her first thought was to write about the women with her who had survived, and the ones who had not. But when she finished her book, with its mixture of memory and testimony, she put it away in a drawer for 20 years, worried in case it did not convey what it had really been like. She wanted to be certain that the writing was so plain, so transparent, that nothing would come between the readers and their understanding.

This sense of absolute directness and immediacy lies at the heart of Svetlana Alexievich’s extraordinary oral history of the Russian women who fought in the second world war, translated by Richard Pevear and Larissa Volokhonsky. Over seven years in the late 1970s and early 80s, she interviewed many hundreds of women, the pilots, doctors, partisans, snipers and anti-aircraft gunners who served on the front line, and the legions of laundresses, cooks, telephone operators and engine drivers who backed them up.

Very few of those she approached refused to talk to her. One former pilot, who turned her down, told her that she could not bear to return in her mind to the three years during which she had felt herself not to be a woman. When, in the ruins of Berlin, her future husband proposed to her, she had been outraged. “How, in the midst of chaos? Begin by making me a woman,” she told him. For the rest, the women poured out their memories to her, not simply recounting them, but reimagining them. The simpler the women, the more their stories were “uninfected by secondary knowledge”.

Alexievich herself was born in 1948 into a family scarred by the war. Close relations had been killed, died of typhus or been burned alive by the Germans. Her father was the only one of three brothers to come home. The talk, in the village in Belarus where she grew up, was all of war; most of its inhabitants were widows. Alexievich left school to become a reporter on the local paper before devoting her life to collecting oral testimonies in order to document what it had been like to live through some of the defining traumas – the Chernobyl nuclear disaster and the fate of the Russian soldiers in Afghanistan – in recent Soviet history. In the days of Tolstoy and Dostoevsky, she has said, she would probably have written fiction. But today, when things happen so fast that the human mind cannot absorb them, “there is much that art cannot convey”. A “writer, reporter, sociologist, psychologist and preacher”, she sees the world as a chorus of “individual voices and a collage of everyday details”.

Soviet pilots Vera Tikhomirova and Mariya Smirnova, 1942. Photograph: TASS/TASS via Getty Images

A million women fought in the Red Army. Alexievich’s project began when she read an article in a Minsk paper about a farewell party given for a senior female accountant who, as a sniper during the war, had killed 75 people and received 11 decorations. War, she realised, is seldom told from the woman’s point of view, and what interested her were not tales of heroism, but of “small great human beings”. What was more, there was nothing heroic about war, which needed to be shown as sickening, repulsive and insane.

A surprising number of the women she spoke to had been desperate to get to the front, drawn by the prevailing patriotic fervour and willing even to abandon young children at home. Many had falsified their ages, lied, pestered. When they got there, they discovered that the reality was not glory but brutality and the events they described to Alexievich are a chronicle of horror, dirt, exhaustion and fear. As women, givers of life, they said they found killing harder than the men. Broken up into statements, some no longer than a few dozen lines, following on from each other without interruption, their stories tell of hearing the skulls of dead Germans crunching under the wheels of lorries, of rats so starving in Stalingrad that they ate knapsacks, of the corpses of sailors in striped jerseys so bloated that they looked like watermelons, and of leaving on missions with their babies strapped to their backs.

And after they had recounted the fighting, they described the ordinary things, the falling in love, the men’s haircuts and uniforms they were forced to adopt, the way they curled their hair with pine cones and sat doing embroidery between the shelling, and how they missed their children. Alexievich took infinite time and patience, sometimes spending whole days waiting for the moment when the past was suddenly unlocked. The intensity was such, the chorus so insistent, that at times she felt she could take no more.

There was little joy in returning home. Many comrades had been lost, and the babies the women had left behind had become children who did not know them. Husbands had disappeared in the war and parents were to be found in shallow graves in the ruins of burnt villages. The Unwomanly Face of War continues into the immediate postwar years, when Stalin was sending dissidents to labour camps in the east, and silence and secrecy became the sole means of survival. Many women spoke to Alexievich of being rejected by men, who came home from war looking for feminine softness and not the toughness that these female pilots, snipers and gunners had acquired. They mourned their lost femininity; they were “unkissed”, and when they got home, even those still only in their early 20s, never felt young again.

Volunteers, who completed military training near Sevastopol, during the second world war. Photograph: Bettmann Archive

Alexievich was largely unknown in the English-speaking world until she won the Nobel prize in 2015, in the face of objections that non-fiction of this kind was not literature. Her most recent book, Second-Hand Time, about the collapse of the former Soviet Union and once again a collection of testimonies, was longlisted for the Baillie Gifford prize. After falling out of favour with the dictatorial Alexander Lukashenko’s regime in Belarus in 2000, she lived in exile in France and Germany until able to return to Minsk in 2011. The Unwomanly Face of War was first published in 1985 but in censored form, the authorities telling her that she should write not about “filth” but about victory. This is the first unexpurgated version.

Alexievich was not the first writer to chronicle the Soviet participation in the second world war through oral history. Ales Adamovich, a Belarusian whom Alexievich describes as her mentor, collected and published narratives from the front, but these seldom came from women. Her years of meticulous listening, her unobtrusiveness and her ear for the telling detail and the memorable story have made her an exceptional witness to modern times. Critics have objected to the lack of all but brief interlinking passages, but if anything the few that are there intrude: the effect of this seamless flow of voices is one of immediacy. Like Delbo’s Auschwitz and After, Alexievich’s book is a map not of events but of the character and emotions of those involved in them. This is oral history at its finest and it is also an essay on the power of memory, on what is remembered and what is forgotten. “It’s terrible to remember,” one woman told her. “But it’s far more terrible to forget.”

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• This article was amended on 7 August 2017. An earlier version said Svetlana Alexievich grew up in Ukraine and referred to Alexander Lukashenko’s regime in that country. This has been corrected to Belarus.