The trouble is that as a society we've completely failed our children.
What I mean is that they no longer grow up with any real sense of aspiration. That isn't their fault. At school they are fed into a system that is no longer concerned with children and is now based entirely on meeting statistical targets. Individual teachers may try to deal with them as human beings, but the overall impression they get is that they only exist as test results. Their families have no time for them, and most of what they experience from the wider world is fear and mistrust. Then to cap it all we don't give them any worthwhile aspirations.
They get told work hard and you might get a job. Then they look around and see somebody working for a pittance behind the counter at McDeadthings, or sweeping the streets, and quite rationally and sensibly they say "fuck that, I'd rather deal drugs". When I was a kid I was told work really hard and with a bit of luck you might be an astronaut, or a barrister, or win a Nobel Prize, or write a best selling novel. Mostly our kids are no longer given those ambitions. We ask them to dream small and get pissed off when they look elsewhere for aspirations.
So they join the local gang. It's a rational decision given the alternatives they are offered. Unfortunately it's a rational decision that leads to crime, violence, and like as not a short and ugly life. However it's not a stupid choice if the only other thing they are being offered is a long and ugly life.
First thing I'd do is scrap the national curriculum as of now. Let teachers teach, let kids learn, and fuck being able to judge which school is better than another according to the league table. The aim of the education system is to educate, not to create statistics that politicians and educationalists can argue about.
We have to give working class children back some real dreams. Realistic goals are fine on a day to day basis, but we all fail to achieve most of our dreams. So why the hell don't we demand that our kids dream BIG. Fail to become something bloody amazing and you might still be bloody amazing. Fail to achieve adequacy and you have a problem. We need to feed them some aspirations, not simply try to lock them into a treadmill of test results all the way through childhood.
They also need to be understood and not feared. We are developing a situation where in parts of Brixton there are parallel and entirely separate societies for the over and under 21s. That can't go on. By and large I find teenagers are fine if dealt with as rational human beings on a one to one basis. Mostly groups of them are fine too. The local gang here on Angell Town is notorious, but it's composed mostly of rational and intelligent kids. Many of the supposedly worst ones are actually the brightest. They just don't get encouraged to show that outside of the gang context.
Finally we need to stop doing things for "the youth" by setting up ways to ghettoise them into "young people's activities". The concentration should be on the activity itself and not on it being something to involve young people. They aren't stupid. They know when they are being offered something that's second rate just to keep them out of the way.
In short we need to deal with kids as young human beings and not as a problem to be solved. We have to offer them something better than being in a gang.