Alexandra Fuller's first book was about growing up in Rhodesia. Her second revisits the region's wars, she tells Shane Hegarty.

Alexandra Fuller's 11-year-old daughter wants to be a writer. "She says: 'You know, so far life's been quite easy for me. You were lucky: you had a very difficult life. I've nothing to write about.' " Fuller ponders this for a few seconds. "She writes beautifully." Then she half-grins. "But, yes, sometimes I think that I've been such a good mother to her that I've nothing to write about."

In her first book, Don't Let's Go To The Dogs Tonight: An African Childhood, Fuller wrote about growing up in Rhodesia, Malawi and Zambia. Of how her parents left pastoral England for a country tipping into civil war. Fuller's mother, an alcoholic, would be haunted by the deaths of three of her children. Her father was a part-time soldier and a farmer regularly defeated by the land.

Little Alexandra - or Bobo, as she is commonly called - learned how to clean and assemble a rifle once she hit five, was taught what to do if "all the grown-ups are dead". The book was both horrible and beautiful, illuminating the naivety of colonials clinging to the nightmare as if it were a dream and not flinching in the details. It irked her, then, when one reviewer recently described her as pretentious. "Gosh, I wish I were," she gasps. "I wish I could be a yoga mum instead of peeling layers of myself off and leaving them lying around for other people to pick up."

In her new book, Scribbling The Cat: Travels With An African Solider, plenty more layers are peeled away. She writes of her journey through Mozambique with a former soldier, a man with a reputation for violence and whose past as part of the Rhodesian Light Infantry, an all-white regiment, included some terrible deeds. "The interesting thing is that there's been an incredibly strong response," she says. "Strongly good and strongly bad. There was no room to feel equivocal about it. Which is perfect, as that is a response we should have about war and to a human being like that."

She had originally planned a follow-up to the book she refers to only as Dogs, and had written a memoir of her adolescence. "I wrote this book, this awful book . . ." So that was shelved, with the good bits portioned out to journals and collections. Then, while visiting her parents in Zambia, an encounter with the man she refers to only as K dropped her into a story in which she retained almost no control. "I don't think it's possible to write something unless it's been given to you to write, by circumstance or something that gave you to feel absolutely driven to do it, and I was."

She constantly returns to the themes of honesty and lies. How society suppresses the former and encourages the latter. How war replaces honesty with propaganda. The honesty in her writing. "It's my greatest, greatest fault. My husband complains that I can be completely honest to a roomful of strangers and very private in my private life. And I think about it a lot. Ultimately, I really don't care if a few million people feel like they know me very well. Because then there's really no, there's no . . ." She thinks about it. "You don't have to wake up with them the next day. And sometimes that can be quite difficult with someone you're married to and should probably be most privy to your dark secrets."

The reviews have been mixed, with several dissatisfied with Fuller's refusal to judge the soldier. "I think one of the things I wanted to do with this book is to take a reader with me and say, look, I'm not writing this like a journalist. It's not dispassionate and distant and all the things it's supposed to be," she says, forcefully. "So what if you took me out of that, my cabin, with the kids and a husband and a dog and computer and lovely life I now have over in America? Why don't you take me out of the element and throw me somewhere where I'm going to be unbalanced? And look at the surprising way that I behave. Not always well.

"How much worse would it be to be taken as a young man and thrown into a war situation? So you can't tell me that if you were a soldier you'd never, ever do any of these things. Because if you haven't been there you don't know. And I think that's really the whole thing about this book, because I wanted to say that, as human beings, we're a bloody mess."

It's a sentiment that echoes from her first book. The success of Don't Let's Go To The Dogs Tonight surprised Fuller, as "eight or nine" of her novels had previously been rejected. They were set in colonial Africa but had "no emotional honesty" and featured too many tea parties and white women being nasty to their black servants. She admits that she has a fear of being known simply as an African writer, of never being able to approach fiction again, but she has once more been drawn towards the continent and a need to write about Africans in a way that "doesn't only treat them as a natural disaster".

She has just spent five weeks back in Zambia, where her parents still live. "It was inspiring. I felt I was with Jesus for five weeks. I saw Zambia completely differently. I really had this sense of an enormous love for the place. And a much better understanding of it. And an enormous, huge compassion for this entire population of people who are forced to love in a time of AIDS."

The story has been told as a Western one, she says, but not as an African one. "You see, this has just occurred to me as I'm talking about it now. I would love to write a story in which you aren't even clear what colour the people were."

She has learned, though, how difficult it is to write about Africa from a white perspective without being battered by accusations of racism. "I'm very bored of the whole issue of racism." She sighs. "It comes up everywhere. It comes up in Africa all the time. I'm bored, bored, bored with it. Because it should be so irrelevant by now. You can't criticise me for having white skin. You can't criticise me for having green eyes.

"I'm honest about what it feels like to have white skin, but I can't change the colour of my skin and I can't change the way people react to me. For me it's all about the honesty, that all I can say is that if I tried to write this from a black point of view then people would criticise me for that. And I don't understand what that feels like, to be honest. I have heaps of black friends. I could ask them, but would I really know it?"

She has considered moving back to Zambia with her family but has instead remained in Wyoming with her husband and two children. She shows me pictures of her children, grinning against a mountainous backdrop. Fuller climbs those mountains to keep the adrenaline going. She has climbed one 13,000-foot peak three times. The second time because she hadn't looked down the first time. The third time to see if she could do it in a day.

"I live my life as furiously as I can. To make sure there is no zone with my name on it whatsoever. I have a vision of an entire culture sitting on one long sofa. There's no sense of adventure."

Scribbling The Cat: Travels With An African Soldier by Alexandra Fuller is published by Picador, £16.99 in UK