AS THE drug war has rumbled on, with little to show for all the money and violence, its critics have become a more diverse bunch than the hippies and libertarians who first backed drug reform. The latest broadside against prohibition was fired on March 24th by a group of former heads of state and businesspeople, who put forward a sober case for rethinking the international approach to drug control.

“Ending the War on Drugs” is a collection of essays by former presidents of Brazil, Mexico, Colombia, Nigeria and Switzerland, as well as a former deputy prime minister of Britain and assorted scientific folk. George Soros, a financier who has bankrolled many pro-legalisation pressure groups, provides a chapter; the book carries an introduction by Richard Branson, a business mogul whose company, Virgin, is its publisher. All condemn what they see as a political, economic and public-health failure.

The arguments are well-rehearsed but bear repeating, especially when made by such a diverse and level-headed group. In spite of its vast cost to taxpayers (estimated by the authors at $100 billion per year) the war against drugs has failed to stop people taking them, instead driving up the price of narcotics to the point where they generate upwards of $300 billion a year for their dealers and traffickers. More than 1.4m drug arrests are made each year in America alone, and they are unevenly distributed, with black Americans jailed for drug offences at ten times the rate of whites, the authors write.

Latin America has borne the brunt of the war, and perhaps the sharpest chapter is by Ernesto Zedillo, who witnessed the narcotics industry’s destructive, corrupting power as president of Mexico in 1994-2000 (even his drug tsar turned out to be working for the Juárez cartel). He spells out that merely decriminalising consumption—in effect, downgrading drug-taking from a serious offence to something more like a parking violation—is inadequate, since it leaves the supply side of the business in the hands of the mob. Indeed, “decriminalising consumption without taking away from organised crime the provision of the supply of drugs would be counterproductive, even disastrous,” he argues. Governments should “intelligently regulate”—that is, legalise—drug markets, he concludes.

The arguments are aimed at the diplomats who next month will gather in New York for a special session of the UN General Assembly to discuss the question of drugs. The last such session was in 1998, when the summit’s slogan was “A drug-free world: we can do it”. That aim has been missed in spectacular fashion—indeed, the consumption of most drugs has risen steeply. Yet the signs are that this year’s summit will be little more enlightened. A meeting of the Commission on Narcotic Drugs, another UN organ, ended on March 22nd with a draft declaration that failed even to criticise the use of the death penalty for drug offences, something that reformers had previously hoped might be achieved as a minimum.

The arguments of the ex-presidents and their allies are persuading growing numbers of the need for a rethink—not least in America, once the arch drug-warrior, where more than half the population now wants to legalise cannabis, and more and more states are doing just that. The trouble is that changing the UN conventions that mandate worldwide prohibition would require the agreement of all 193 member states, and plenty are still firmly against even tentative reform. The most likely outcome of next month’s powwow is more waffle, and a growing realisation that the UN drug conventions will not be reformed but simply ignored.