The eruption of the underbelly of Britain's cities should come as no surprise. I've seen it at first hand over the past two years, when I was embedded with front-line police units in inner-city London, Manchester and Glasgow. Ever younger children are being drawn in ever larger numbers into petty street crime and gang activity. Looting is just more of the same.
On one chronically deprived estate in Easterhouse, Glasgow, a 13-year-old was given a machete by his mother on his birthday to protect himself. In Southall, west London, I spent time with a 14-year-old "enforcer", a former child soldier from Somalia, who had arrived on an inner-city estate to find his experience with guns was sought after by the local "olders". He was recruited and exploited for money in London just as he had been in war-torn Mogadishu.
Other patterns emerged. I spoke to a 19-year-old gang member in Moss Side, south Manchester, who'd just headbutted a policeman, and a 15-year-old in the East End of Glasgow who was awaiting trial for disfiguring another teenager with a golf club. Both were fatherless, trying to be "the man of the house", in keeping with a warped, ultra-macho street code. The 15-year-old got off when no witnesses came forward.
I sat in the back of unmarked police cars with detectives who were underpaid, overworked, exhausted and frustrated by bureaucracy and form-filling. One 48-year-old policeman in Manchester had torn a hamstring pursuing a twentysomething gang member who was also a semi-professional footballer. Another cop had his leg run over by a gang member in a getaway car. I worked out that one detective working back-to-back 3am shifts was being paid £716,000 less than the 31-year-old drug baron he was pursuing. The trial that convicted his quarry went on for six months, viewed 8,000 pieces of evidence and cost £5m.
In the course of my research, I came to understand how drugs policy - which hasn't changed in 30 years - needs to be far more open to new and experimental ideas. That convicted dealer in Manchester was persuasive, charismatic, entrepreneurial. Would he have used these gifts differently if he had been born, like David Cameron, to three generations of stockbrokers, rather than in a cul-de-sac in a deprived part of Manchester?
It made me think that Britain has been two countries for some time now. There is the Britain that everyone knows, with its thriving, middle-class economy. But decades of failed policies have created inner cities that no one talks or reports about, like a third world country or a war zone. These deprived areas have experienced the growth of teenage gangs, a rise in knife crime and terrible youth violence.
There are two particularly alarming trends. First is the youth of those drawn into petty street crime and gang activity. Three-year-old toddlers in the Nottingham North constituency of the Labour MP Graham Allen turn up for nursery "incapable of resolving differences without violence", according to Ofsted inspectors quoted in a Centre for Social Justice report. From a very early age, kids are told that their lives will amount to nothing. They start to believe it, fall behind at school, truant, drift into delinquency and end up in a young offenders institution at the cost of £60,000 a year. And the cycle continues. A quarter of young offenders are already fathers. Patrick Regan of XLP, the inner-city charity, states that 63 per cent of violent fathers have sons who go on to offend.
The lack of jobs does not help. Last year, I went out with Strathclyde Police's B Division, based in Shettleston, Glasgow, one of the most deprived areas of the UK. Men's life expectancy here is 63, 14 years lower than the national average - closer to Iraq or the Palestinian territories than the UK. As the officers piled into the van, they passed a container of confiscated weapons: hatchets, swords, scaffolding poles. The Strathclyde force's Violence Reduction Unit now treats violence as an infectious disease, passed on by parents or friends. Funding to tackle it comes from the health budget.
The influx of drugs is another factor. Southall is one of the cheapest places in the UK to buy heroin, and the £4.5bn-a-year drug trade is the most dynamic, entrepreneurial business in the inner cities. In parts of inner London, olders loiter at the school gates, wearing their jail muscle and time inside like a badge of honour. They are intent on recruiting little men of steel into their crew. More efficient and persuasive than any careers service, they groom them, give them new trainers or £50 to draw them in. Given that the big players can earn £130,000 a year from drug-dealing, it's hard for working in Tesco, or plastering, to compete.
The drug trade runs on violence. On 7 August 2007, one boy on a south Acton estate who refused to deal was thrown in a lift naked with a pitbull and sent to the 15th floor of Blackmore Tower. The Somali olders in Southall would take other reluctant boys to the local park and lash their bare backs with whips, a detective sergeant told me in 2009. If you grow up in a war zone, you become a warrior.
My two years on the streets taught me that we need to take a long-term interest in young people in our inner cities. When no one cares about you, you are less likely to care about smashing a shop window. And in the end, street violence was always there; we just chose to ignore it.
Gavin Knight is the author of "Hood Rat" (Picador, £12.99)