In the late 1970s, when Carolyn Forché was twenty-seven years old, an enigmatic man turned up at her door with his two young daughters. Leonel Gómes Vides was a cousin of a friend and had driven to Southern California from El Salvador. As his daughters played with Forché’s pet rabbits, he explained the entire colonial and postcolonial history of Central America, before asking her to return with him to his country. Vides was convinced that there would soon be a war in El Salvador and wanted Forché to witness it.

Forché was not sure she’d be of any use: she was a poet, and poets in the United States, she told him, were seen as ‘bohemian, or romantics, or crazy … We have no credibility.’ Leonel replied, ‘In my country, and in the rest of Latin America, poets are taken seriously. They’re appointed to diplomatic posts, or they’re assassinated, or put into prison but, one way or the other, taken seriously.’

Forché was young, but not all that inexperienced. She had already been married, aged nineteen, to a soldier fighting in Vietnam (she does not name her first husband in the book, giving only his surname, which is the one she bears). Vides told her she had the chance to see in El Salvador what he called ‘Vietnam, from the beginning’. It would provide her with material. ‘What are you going to do … Write poetry about yourself for the rest of your life?’

Forché went with Vides, and he delivered. The material she collected formed the basis of her poetry collection The Country Between Us (1981). The title of this memoir, What You Have Heard Is True, is drawn from her poem ‘The Colonel’ – a striking vignette of her time in El Salvador. The titular colonel spills a sack of ears onto the table and then declares, ‘Something for your poetry, no?’ Forché is conscious of her privileged and awkward position as an outsider in El Salvador, a tourist, a consumer of violence, one who is free to leave.

There has been an understandable backlash in recent years against ‘white saviour’ narratives, in which someone from the developed world positions him- or herself as central to the story, rescuing confused natives from peril. There are grounds for such a critique of this book: it is a memoir of personal growth set against the collapse of a country; some may feel that more pressing stories might emerge from the collapse of a country than a foreign poet’s personal growth. In the book’s defence, it is not quite as clear cut as that. Forché is not a complete outsider. The US government was heavily involved in the Salvadoran Civil War: fearing that a leftist insurgency would lead the country into communism, it poured money into the coffers of the viciously oppressive military regime. As an American civilian on the ground, opposing the actions of her government, Forché has a perspective that is interesting in its own right. She has no sense of acting as a saviour, but only as a witness, as Vides requests. She engages constantly with the question of what it means to see without doing. She is well qualified to witness: she speaks Spanish, observes precisely and writes with a startling, visceral clarity about grotesque events.

There is a lot of horror in this book. People are thrown from helicopters into the sea, their arms tied behind their backs. A colonel grinds up his victims’ bodies and feeds them to his dogs. Forché finds mutilated corpses by the side of the road. She visits a prison where men are kept in cages the size of washing machines. She and a friend are pursued by an escuadrón de la muerte (death squad). Later, she meets a man who was a member of one such squad, who recalls the sound of bubbles as he cut his victims’ throats.

‘Look at this. Remember this. Try to see.’ This is Vides’s constant refrain. Yet he permits her to see little of himself. In a tantalising scene, he shows her ‘one place’ he lives. He offers her a bed with a poster of Che Guevara over it, pulling back the covers to reveal an AK-47. ‘Someone else also lives here,’ he says vaguely. She dares not ask about the gun, but mentions the poster of Che. ‘Yes, well, I have posters of Mussolini too, if the need arises,’ he replies.

Unquestionably, Forché has done what Vides asked. With her poems, and now with this exceptionally well-written and engrossing memoir, she has borne witness, remembered, tried to see. She has spent many years of her life telling the stories of El Salvador to a primarily American audience whose government has been complicit in its suffering. What You Have Heard Is True paints a stark, tangible and unforgettable picture of a nation descending into civil war and raises fascinating questions about the role of the observer.

Forché’s readers also act as witnesses, second hand. Her writing has a way of scratching images into the memory. Some of the most striking lines come in Forché’s notebooks, written while she was in El Salvador, which read like prose poems:

El Playon ‘the beach’ is a rock strewn with refuse and sea wrack a body a tin spoon bottle glass purple from the sun a paint can a skull with hair a shoelace trousers more bodies flocks of vultures fattening themselves on the ground a stripped spine a broken plate a palm open to the rain. El Playon is a body dump. ‘Yo lo vi,’ Goya wrote beside his sketches. ‘I saw it, and this, and also this.’