ONE of the lesser-known of London’s many amazing sights is the Mandela Way T34 tank. This remnant of the Second World War sits on a patch of scrubland just off the Old Kent Road, surrounded by litter and weeds. Every few weeks, it changes colour, spray painted by inventive graffiti artists. When I last visited, it was entirely gold, looking like the personal battle tank of a mad central Asian dictator. And as I admired it, a drunk man, perhaps 60 years old, delivered a racist rant. Pointing at a CND logo someone had painted onto the gold, he said that “that’s bullshit, that’s why we need tanks. You’re white and British, you’re alright. But we need to defend ourselves.” Half way through this invective, a young black kid walked past and shouted out “when are you going to stop drinking granddad?” Of course there have always been elderly, angry alcoholics, spending their time sprawled out on park benches and wandering the aisles of off licences. But the tank aside, this scene struck me as a rather typical scene of modern Britain. As we report in our briefing today, in Britain and elsewhere, young people are getting ever more responsible. They are proving less likely to take drugs or drink than past generations. Very few have serious problems with alcohol or drugs. The social ills we have, increasingly, are problems of the relatively old.

Take alcohol. Alcoholism among the young is what upsets the Daily Mail, which every New Year's Day likes to publish photos of young men and women somewhat worse for wear on the previous evening. But these days, it is people in their 40s who are most likely to be admitted to hospital for drinking too much. Actually, Britain’s problem drinkers tend not to be young people, who may binge drink occasionally, but most of the time are fairly sober. They are more likely to be middle-aged Mail readers, drinking yet another bottle from their Mail Wine Club delivery each day, slowly building up an addiction that eventually lands them in hospital.

Other statistics tell a similar story. The latest figures on drug addiction from Public Health England show that 39% of heroin addicts are now over the age of 40, up from 19% in 2006. Fewer than ever are under the age of 24. The number of young adults in prison is falling, but our overcrowded prisons increasingly as home to greying men: between 2002 and 2013, the number of men over the age of 60 locked up increased by 130%. The same is true of suicide rates: on both sides of the Atlantic ocean fewer young people but more middle-aged men are killing themselves.

These problems are more entrenched than the problems of youth. As William S Burroughs wrote in Junky, “You don’t wake up one morning and decide to be a drug addict. It takes at least three months’ shooting twice a day to get any habit at all.” And habits which take time to build up are not easy to kick. From the state of him, I suspect the ageing drunk I met in Bermondsey had been drinking for much of his adult life. Middle-aged heroin addicts are less likely to rob people in underpasses or go burgling houses to pay for their habit, but that sort of crime is easy enough to prevent. It is far harder to get long-standing addicts clean.

Not only are older people’s problems more entrenched, they are more spread out. The most deprived places in Britain are no longer wards of Tower Hamlets, but rather places like Jaywick, a tiny village near Clacton-on-Sea in Essex where impoverished pensioners spend their days in dilapidated 1930s-built seaside shacks. The same is true in America and many European countries, where cities have been fixed but rural poverty remains endemic. Attracting good social workers and money to such places is not easy.

In the future, we may look back at when we were obsessed with the problems as youth as an easier era. Teenagers and young adults are fairly easily policed, both by their parents and by the authorities. They don’t vote, and so they are easy for politicians to attack. David Cameron’s misguided campaign against “Broken Britain” almost entirely focused on youth. Attacking the middle-aged is far more difficult. After all, alcoholics are voters too.