Guantánamo Bay's days may be numbered, with President Obama's pledge to close the detention camp, and prisoners trickling home, but children's writer Anna Perera is determined that teenagers, at least, will understand the full horror of the human rights abuses that took place in the name of the "war on terror".
Perera is the author of Guantánamo Boy, a novel that pulls no punches in its depiction of the torture, isolation and injustices suffered by prisoners at the notorious camp. The book focuses on Khalid, an ordinary 15-year-old from Rochdale who spends his time playing computer games, hanging out with his mates in the park and wishing he had the guts to tell his Irish classmate Niamh that he fancies her. However, within days of arriving in Karachi on a family visit to relatives, Khalid's life turns into a Kafkaesque nightmare when he is abducted from his aunt's house and ends up being held for two years, without charge, in the world's most notorious prison.
It sounds unlikely but, according to Perera, it is well-established that juveniles have been held at Guantánamo, although the numbers are disputed. Reprieve, the charity for prisoners from death row to Guantánamo, has recorded that 22 under-16s have been held at the camp. The youngest juvenile still in custody is Mohammed el Gharani, who was 14 when picked up in a random raid on a mosque by Pakistani bounty-hunters and "sold" to the American authorities for $5,000.
It was stories like these that Guantánamo Boy is based on, although the book itself emerged out of just one line delivered by the human rights lawyer Clive Stafford Smith at a benefit event for Reprieve in 2006.
"At that gig Clive Stafford Smith simply said 'children are also held in Guantánamo Bay' and that one statement inspired this novel," says Perera. "The title came to me immediately. At that point I began reading and researching on a daily basis and formed an opinion and a story."
Perera cites the book Enemy Combatant by former Guantánamo inmate Moazzam Begg, the play Guantánamo by Victoria Britten and Michael Moore's film Sicko among her source materials for Guantánamo Boy, having made a conscious choice not to speak to any former inmates about their specific experiences.
"I made the decision not to have any conversations with anyone who had links to the prison because those people's stories belong 100% to them and didn't want to take that from them or imagine myself being them - that felt immoral. I wanted a fictional character who I could say and do what I wanted."
She has certainly made a considerable imaginative leap from her own life, as a full-time children's writer, married to founding member of Dire Straits David Knopfler and resident in a Hampshire village. But she shrugs off any doubts about her ability to give authentic life to Khalid.
"Boys are boys," she says. "I have taught adolescent boys and raised a son so it was not in the slightest bit difficult - that's what writers do, they inhabit their characters absolutely."
She does, however, admit to "plenty of nerves" about other people's reactions while writing it. "I thought I might get slated for being a middle-aged woman writing as a teenage Muslim boy. I came up with every angle that they could come up with to criticise it," says Perera. "But the world has changed since I was writing it and there has been no criticism at all; rather, there seems to be a welcoming instead. The story, the subject, was a gift that was ready to be unwrapped."
It is a "gift" that is, at times, difficult to read for its brutal portrayal of how a human being can be broken down. The bulk of the book details the unremitting hell of the days, weeks and months of Khalid's life that pass by in Guantánamo - the isolation; the head-shaving; the shackles; the endless interrogations; the "terrifying screams" from the other end of the building; screams of Khalid's own. The chapter in which Khalid is "waterboarded" until he signs a false confession, in which Perera gives a moment-by-moment description of a "slow-motion drowning" in ice-cold water, is particularly gruelling. Was it hard to write?
"There were times when I didn't want to write it but had no choice," says Perera. "I wasn't in a state of fury - each day, before I wrote a single word, I meditated and detached from the subject I was writing about. It worked for me because it opened me up. Writers inhabit a space between two worlds; in order to write well you have to go into that space between those two worlds, not always writing consciously. You're opening your mind and allowing words to arrive and that's how I worked on this book. It was the only way I could write about this subject and be at peace."
Perera was determined that, despite its punishing subject matter, the teens who read the book would experience that same feeling of peace by the end of it. Tiny instances of humanity lighten Khalid's life in Guantánamo - a prison guard who gives him a piece of chocolate; the arrival of a yellowing Reader's Digest copy of To Kill a Mocking Bird, which Khalid devours over and over again; a sudden glimpse of blue sky from the exercise yard - and the ending offers a glimmer of hope for the future.
"I had no desire whatsoever for children to go out and be angry as a result of the book so I spent a lot of time accenting my message of peace," explains Perera. "Kids don't like books with messages - they don't want to be preached at - but there is an underlying humanity in the book.
"Children want the truth to be told but not in a preachy way. When they're presented with loads of facts they switch off - we all do. It's only through stories that we understand issues that are sometimes difficult to comprehend. To me, all books are devices that help people understand the world that they live in, appreciate it, and ponder their own existence. What I hope is that teenagers will see the similarities between themselves and issues that are on the news every day."