In a major keynote speech today, Nick Clegg will call for responsibility for drugs to be moved from the criminal justice system to the health care system. In that, he has the support of Richard Branson and the two men have written for the Guardian’s Comment is Free section. First of all, they show how the current system is both wasting money and failing:

 Since the “war” was declared by President Richard Nixon in 1971, we have spent over £1tn trying to eradicate drugs from our societies. Yet the criminal market continues to grow, driving unimaginable levels of profit for organised crime. We devote vast police, criminal justice and military resources to the problem, including the incarceration of people on a historically unprecedented scale.

In many parts of the world, drug violence has become endemic. As Mexico’s president, Enrique Peña Nieto, visits the UK, we should remember the estimated 100,000 people killed in Mexico alone since 2006. Yet tragically, the sum total of enforcement efforts against drug supply over the past 40 years has been zero. Efforts at reducing demand have been similarly fruitless. Here in the UK, a third of adults have taken illegal drugs and the gangs are doing a roaring trade. The problem simply isn’t going away.

While other countries around the world are rethinking their approach, Britain remains stubbornly, truculently wedded to the old way, with tragic human consequences:

And yet we desperately need better solutions in this country. One in six children aged 11 to 15 is still taking drugs; 2,000 people die each year in drug-related incidents; the use of unregulated “legal highs” is rampant.

At the same time, the police are stopping and searching half a million people a year for possession of drugs, prosecutions of users are close to record levels, and prison cells are still used for people whose only crime is the possession of a substance to which they are addicted. This costs a lot of money, which could be better spent on treatment and on redoubling our efforts to disrupt supply. And it wrecks the lives of 70,000 people a year who receive a criminal record for possession and then find themselves unable to get a job.

As an investment, the war on drugs has failed to deliver any returns. If it were a business, it would have been shut down a long time ago. This is not what success looks like.