In 1983, Carmen Bugan's father, Ion, put on his best dark suit and drove to Bucharest to radically change his family's life for the worse. He stopped his red Dacia car on a rush-hour street and mounted banners on the roof. "Criminal, we don't want you to lead us" announced one. "What do you defend, the Ceausescu dynasty or the rights and liberty of man?" said the other, directed at the army, judiciary and police.

Romania was in the grip of the totalitarian Ceausescu regime. At home, 12-year-old Carmen was convinced her father's one-man protest would end in his death. "I thought it was a suicide mission. It felt a lot like abandonment. I wasn't quite ready to sacrifice my father for any political ideal," she remembers now.

She was also angry. "For a long time I felt that somehow we were less important to him than the case of Romania."

Ion had certainly chosen his moment. His wife, Mioara, was in hospital, after complications during the birth of Carmen's younger brother; her sister was away doing gymnastics. It was left to Carmen and her grandmother to face the Securitate, the secret police, who interrogated them, and turned their home upside down in an attempt to discover the extent of Ion's treachery. Carmen did not know if her father was dead or alive.

Twenty-three years later, Carmen, a poet who lives on the border of France and Switzerland, has written a beautiful, vivid memoir of growing up in Ceausescu's Romania – Burying the Typewriter – a childhood idyll gradually supplanted by a growing awareness of oppression. Her parents ran a grocery and she witnessed the food shortages and fighting over rations.

But until her father's ill-fated protest, the clearest inkling she had of her parents' activism was when she found her father burying their typewriter in the backyard. Every night she heard the keys clacking, as her mother and father wrote forbidden pro-democracy pamphlets; by day, she learned of other moments of dissent in the east, via Radio Free Europe.

When her father vanished, she realised that her mother had helped him with the flyers not just because she believed in what he was doing: "More than that, it was a dedication to her family. She felt if she helped him they would stay secret," she says.

With his wife in hospital, years of pent-up political activism exploded in Ion. "My father didn't feel so supervised by my mum. He felt more free to focus on this work because my mother wasn't there to remind him how dangerous it was and try to stop him."

For her father, she says, "It was now or never, a desperate thing." But he also understood the risks. "He knew all about torture, about being followed and punished for his political beliefs. He was prepared for the sacrifice."

"It didn't feel like he sacrificed himself," she pauses. "It felt like he sacrificed us as well."

Ion wasn't killed, but he was imprisoned. Microphones were hidden in their home; even in private, Carmen and her family could never speak openly about what they felt. Villagers and friends were forced to inform against the family. Teachers turned against the children at school, and incited other pupils to bully them. The police found the typewriter buried in the backyard. Mioara was banned from teaching and forced to divorce Ion.

Ion was released in a national amnesty to relieve overcrowded prisons in 1987, but the surveillance got worse.

Despite the anger that Carmen and her mother felt towards Ion, the family grew closer. "You would think something like this would tear people apart – the reproaches, the regret, prison. It worked the opposite way with us." Their oppression drew them closer; they couldn't trust their friends or community. "I always felt we were five fingers on a hand – one of us couldn't achieve anything without the other," she says of herself and her parents, sister and brother.

"We were forced by necessity into a trust that is very rare in life. It was beautiful. We developed very close relationships. We would read each other's minds. We were each other's shadows."

Aged 18, Carmen sought asylum at the American embassy in Bucharest. With help, she evaded the secret police, made contact with the embassy, and applied for refugee status. "It was one of the greatest moments of my life – I had a role," she says. Only later did she learn that her father had been Amnesty International "political prisoner of the month" in 1986 and was also championed by Index on Censorship. Western publicity may have stopped the Romanian authorities from making her family disappear.

When they did leave the country, the official at the passport office gave them a chilling warning: if they ever spoke out against Ceausescu they would be hunted down and killed.

As they crossed the border into Yugoslavia, a fellow passenger on the train offered them a sip of Coca-Cola. Their father made the passenger drink it first; he was afraid of being poisoned. Shown it was safe, they all sipped this symbol of the west, "as if it was holy water" remembers Carmen.

In the weeks after arriving in their new home in Grand Rapids, Michigan, in November 1989, she was still terrified, mistaking Jehovah's Witnesses and peeping toms for the Romanian secret police. (It is hard to know who would be more insulted.) Suspicions died hard.

After all those years, did her family struggle to relearn how to express their true feelings once they were safe in America? No, says Carmen, they talked straightaway; her parents are not the kind of people to hide their feelings. In any case, there was a kind of mental liberation: that Christmas in 1989, the church group that first gave them a place to stay discovered the family "dancing and screaming and crying" in front of the television set: there had been a revolution in Romania; President Ceausescu was finally deposed.

Her father wanted to return to Romania; revolution was his "biggest dream and it was happening without him". But his wife and children insisted on staying in America. "We were very tired people," says Carmen. "It felt like there was nothing to return to."

They became model political refugees and immigrants. Carmen was the first to get work, aged 19, as a cleaner, and her mother and sister became nurses. Her father got a job as a school caretaker and her brother is now serving in the US army in Afghanistan.

Carmen studied at Michigan and Oxford Universities and became a poet. Writing about her childhood was a way of reawakening positive feelings for a country from which she still felt estranged. However, her feelings about the past were transformed again when she decided to call up her secret police files, now accessible in Romania's state archives. In a bureaucratic mix-up, she was handed her father's files: 18 volumes and nearly 1,500 pages.

Suddenly, she had an oppressive state's view of her private family life; a strange new "archival identity" as she calls it. She learned that her father – codename Andronic – had been monitored since 1961 after making admiring comments about America's race to land on the moon.

She discovered more about his three prison sentences, his time in solitary confinement – and the torture he had experienced. Some revelations were unsettling: she read a letter in which Ion's father disowned him when he was first imprisoned; her grandfather is now dead and she will never know if this letter represented his true feelings. The surveillance provided an odd, voyeuristic view of herself but some of the things on file were "magical". Bizarrely, the secret services kept a short story she had written, aged 11, on their forbidden typewriter. In another file from 1973, the man spying on her father noted: "He has two young children for whom he cares very much."

Carmen is still very close to her parents, who are now retired, but she struggles to have a relationship with Romania. She lives on the border between France and Switzerland, where her husband works at Cern, the European Organisation for Nuclear Research. "I think I belong on the border. I feel safer psychologically if I have two countries, two places to go," she says.

She also feels half ashamed of being Romanian: "For a government to do that to its people was shameful." Even now, 23 years on, she only has two close Romanian friends. "I'm still suspicious," she says. "You keep wondering what their past was – were they on the side of informers? Were they on the side of the secret police?"

Returning to Romania two years ago to revisit her family home and old school was "one of the worst experiences of my life", she says. Yet there is still an inescapable desire to reconnect. Her writing is circling ever closer to Romania. "Do I want to turn back?" she wonders. "Is Romania really the sun and am I the sunflower?"

• Burying the Typewriter by Carmen Bugan is published by Picador, £16.99. To order a copy for £13.59, including free UK p&p, go to theguardian.com/bookshop or call 0330 333 6846