To many people, the “war on drugs” sounds like a metaphor, like the “war on poverty.” It is not. It is being fought with tanks and sub-machine guns and hand grenades, funded in part by your taxes, and it has killed 28,000 people under the current Mexican president alone. The death toll in Tijuana — one of the front lines of this war — is now higher than in Baghdad. This week another pile of 72 mutilated corpses was found near San Fernando — an event that no longer shocks the country.

Mexico today is a place where the severed heads of police officers are found week after week, pinned to bloody notes that tell their colleagues: “This is how you learn respect.” It is a place where hand grenades are tossed into crowds to intimidate the public into shutting up.

Licence to kill

Why? When you criminalise a drug for which there is a large market, it doesn’t disappear. The trade is simply transferred from off-licences, pharmacists and doctors to armed criminal gangs.

In order to protect their patch and their supply routes, these gangs tool up — and kill anyone who gets in their way. You can see this any day on the streets of a poor part of London or Los Angeles, where teenage gangs stab or shoot each other for control of the 3,000 per cent profit margins on offer.

Now imagine this process taking over an entire nation, to turn it into a massive production and supply route for the Western world’s drug hunger.

Why Mexico? Why now? In the past decade, the US has spent a fortune spraying carcinogenic chemicals over Colombia’s coca-growing areas, so the drug trade has simply shifted to Mexico. It’s known as the “balloon effect”: press down in one place, and the air rushes to another.

Today, 70 per cent of Mexicans say they are frightened to go out because of the cartels. The gangs offer Mexican police and politicians a choice: “Plata o ploma.” Silver, or lead. Take a bribe, or take a bullet. President Felipe Calderon has been leading a military crackdown on them since 2006 — yet every time he surges the military forward, the gang violence in an area massively increases.

Drug trade deeply Rooted

This might seem like a paradox, but it isn’t. If you knock out the leaders of a drug gang, you don’t eradicate demand, or supply. You simply trigger a fresh war for control of the now-vacant patch. The violence creates more violence.

There is a growing movement in Mexico to do the one thing these murderous gangs really fear — take the source of their profits, drugs, back into the legal economy. It would bankrupt them swiftly, and entirely. And, after legalisation they would be in the hands of unarmed, regulated, legal businesses, paying taxes to the state, at a time when we all need large new sources of tax revenue.

How many people have to die before we finally make a sober assessment of reality, and take the drugs trade back from murderous criminal gangs?