Anthony Horowitz: Locking up our youngsters leaves society in shackles

What most worried me was the sense of inevitability that brought them here; the feeling that, from the very start, there was to be no escape

(Darren Diss)

Consider the following two perspectives on our over-crowded prison system. "A costly and ineffectual approach that fails to turn criminals into law-abiding citizens... banging up more and more people for longer without actually seeking to change them is what you would expect of Victorian England." Or, alternatively: "A key factor in reducing crime has been the increased number of offenders sentenced to prison."

It's indicative of the topsy-turvy world in which we live that the first view is that of a Tory Justice Secretary – Kenneth Clarke no less, making a much publicised speech to the Centre for Crime and Justice Studies in London. While it is Jack Straw who now reveals himself to be the fully paid-up member of the lock-'em-up-and-throw-away-the-key brigade. It makes you wonder what's going on here. Has Clarke looked at the facts and had a truly Damascene conversion or is it the possible saving of a proposed £4bn prison building programme that's really at stake?

Either way, the argument is long overdue, and nowhere is this more true than in my own area of interest: youth offending. Can we actually be comfortable with the fact that, proportionally, we imprison more children than any other country in Western Europe? There are around 4,500 people under the age of 18 locked up here, which doesn't compare that favourably with, say, Finland. They have just two. And it seems odd that the culture of violence and bullying that the prison inspectorate found at Youth Offender Institutes (YOIs) such as Cookham Wood and Castington can sit side by side with our deep-felt, sometimes even hysterical concern for young people. Perhaps criminals don't count.

One startling and significant statistic has been quoted by many newspapers. It would currently cost you £28,851 per annum to send your child to Eton. A year in prison comes in at almost twice as much – £45,000 – and doesn't include classical Greek. Even if you're as much of a lip-smacking martinet as Jack Straw, this is hardly good value. According to the Ministry of Justice's own figures, around 75 per cent of children sent to prison will reoffend within a year of release. I have become an occasional visitor to a number of YOIs and it's quite instructive to meet some of the people – the thugs, yobs, little bastards or whatever you want to call them – that are at the centre of this debate.

At the time of the election, I got together with a group of inmates at Warren Hill, which is set in a rather lovely corner of Suffolk, surrounded by woodland, daffodil beds and, in the distance, a sparkling sea. Not that the views are quite so spectacular on the other side of the walls and the razor wire. But I have to say that the place impressed me. Its governor, Roger Plant, is benign and far-sighted, leading a staff that seems genuinely committed to giving some sort of positive steer to the young people in their care. "You need to engage the kids in something that is relevant to them," their community projects officer told me. "Build programmes that address not just their offending but who they are and what they might become." It's odd how closely his words mirror Clarke's.

The outcome of the election meant nothing to any of the kids. "I hate politicians!" exclaimed Ryan, 16, from Essex, although he couldn't actually name any apart from Gordon Brown and he wasn't quite sure what he did. Not that he was unintelligent. He claimed to have six GCSEs and for what it's worth, he was a fan of my books. But some sense of injustice had, inevitably, percolated its way down. "Politicians are corrupt. I'd go to jail for fraud; they get nothing," he went on. Someone mentioned the grandmother (Joan Higgins) who had been tagged for selling a goldfish and this brought indignant laughter all round. "The Government's stupid." Nobody could understand why mephedrone – or meow-meow – has been made illegal when cigarettes were allowed to kill thousands of people, a point of view with which I found it hard to disagree.

All of them had taken drugs at one time or another but denied that drug use had brought them here. "I'm not addicted to weed. I just like the feeling of being stoned," said Darryl, 17, from Dagenham. Jason, also looking forward to his release, said: "The first day I'm out of here, I'm going to smoke the biggest joint ever." The group had a typically idiosyncratic take on drugs classification. Class B drugs are socially acceptable. "Crack is nasty. Weed is like smoking a fag."

I have to admit that I found all these boys strangely likeable, utterly immoral and full of energy. Their world is so far removed from mine that I'd be surprised if the politician existed who could reach them in any meaningful way. Their language is colourful and profane. "Doing blowies for a Radox," an accusation that was levelled at one of them, is a phrase that is unlikely to find its way into my children's books. All in all, they're trying to make the best of a bad lot. And forget the idea that prison is a soft option. Yes, they have televisions in their cells – but it's a privilege that has to be earned and without some sort of reward system how can discipline be maintained? "I'd love people to come here and see what we have to put up with," Darryl said. There was a chorus of agreement. "You can't see your family." "You get five minutes on the phone." "You can't eat when you want to eat something... you're even told when you can wipe your own arse." "My mum cries every time she comes here." "We're only allowed five minutes on the phone."

And well-deserved, many people might say. But what most worried me was the sense of inevitability that brought them here; the feeling that, from the very start, there was to be no escape. I spoke to a second group in the Carlford Unit, close to Warren Hill. It's home to young men who have committed very serious crimes – some of them have been sentenced to life.

I asked these boys where the troubles started. Kevin was aged 17, a quietly spoken and deep-thinking black boy (all the boys I met at Carlford were black or mixed race). He was unequivocal: "School, school, school." It was an unconscious echo of Tony Blair's famous mantra.

James, aged 16 and producing some impressive creative writing, told me his story. He was kicked out of school aged 12 ("I had a fight") and sent to a Secure Training Centre. "No school wanted me after that because I'd been to an STC. I made money selling drugs. I had no choice. There were no Youth Clubs and nothing to do."

Every one of them told me a similar story, a sense of crossing a line after which there could be no hope. "The moment I got kicked out of school, I was out of control," Darryl said. "I got nicked for one thing, then another and another." He told me that his first offence was kicking a ball through a window. His second was being a passenger in a stolen van. But after that: "Every cop that saw me, knew me... and they just thought – he's a criminal."

Daniel, 17, from Northampton and in prison for a second stretch, said the same thing. He claimed to have been stopped and searched 18 times in one week. What really angered him was that this happened in front of his neighbours, so the local community knew him for what he was, too. He put it bluntly. "Once they know who you are, you're fucked."

And this is the very heart of the problem. "If I'm from Stratford and the whole place has given up on me, what am I supposed to do?" Kevin asked, reasonably enough. "People see you in the very worst possible light and look down on you. It makes the community push you out and punish you." In other words, it's a self-fulfilling prophecy. You tell a boy he's bad enough times, he'll prove you right.

I tested this theory on Roger Plant, who has 40 years' experience in prisons and displays an easy, respectful relationship with his young charges. He had not been present at my discussions but supported their point of view: "A taste of prison is never the answer to anything. You lose your family, your friends, your ties. We have to stop criminalising children. The community owns them and the community must take responsibility for them. If your family has dumped you and your community has dumped you, you have nowhere to go."

Nowhere is exactly right. According to the Prison Reform Trust, just 36 per cent of people leaving prison go into education, training or employment and the figure may well be lower for young offenders. For the rest, a return to crime seems to be the only option.

Ben, 17, admitted that Warren Hill had helped him. He's gained a health and safety certificate and has passed Level 2 English and Maths. "But nobody will give me a job anyway..." he added, gloomily. Kevin had been studying for his GCSEs and wants a career in sound engineering. "Is society going to give us a second chance because we've been inside? I hope I'll get a chance to turn things round."

But he didn't sound too optimistic and when I asked the group where they thought they would be in 10 years' time, there was a long pause, and then a single word: "Prison".

And this is of course the long-term cost of a system that is clearly doing nobody very much good. It is perfectly summed up by the webpage of the Centre for Social Justice set up by – again, it's a Conservative – Iain Duncan Smith. "Custody is clearly neither a protective nor a productive place for children. Once a sentence is complete, many of these young people turn back to crime and end up back in the system as adults. The human and financial cost to society of such failure is staggering."

Kenneth Clarke is asking exactly the right question: "Does ever more prisons for ever more offenders always produce better results for the public?"

Unfortunately, the answer may well stick in the throat of his own party and will get short shrift from many sectors of the tabloid press. "One of my strangest discoveries as director of Liberty," Shami Chakrabarti told me, "has been the way we get more angry mail for sticking up for kids in trouble than we ever do for arguing for the rights of terror suspects. Children and young people are one of the most marginalised groups on the planet and quite literally disenfranchised."

Spending time with young offenders at Warren Hill, it's easy to see the truth in this. The boys think of themselves as victims and I've tried to avoid the word as using it will make so many teeth grind. But we somehow created them. They didn't just happen.

"I've got no hope," a boy called Aaron told me. "Nothing's ever going to change for me."

I don't know what he did. I don't know how long he will be in prison. But for any intelligent 17-year-old to have arrived at a state of complete hopelessness so early in his life can't be right.

Surely, as a society, we can do a little more to help.

Anthony Horowitz is an author and screenwriter. His best-known books feature the reluctant teenage superspy Alex Rider. He also created 'Midsomer Murders' and 'Foyle's War'. He is currently working on the ninth Alex Rider adventure. For more information, see anthonyhorowitz.com.