“Least bad” does not mean good. Legalisation, though clearly better for producer countries, would bring (different) risks to consumer countries. As we outline below, many vulnerable drug-takers would suffer. But in our view, more would gain.
Nowadays the UN Office on Drugs and Crime no longer talks about a drug-free world. Its boast is that the drug market has “stabilised”, meaning that more than 200m people, or almost 5% of the world’s adult population, still take illegal drugs — roughly the same proportion as a decade ago. (Like most purported drug facts, this one is just an educated guess: evidential rigour is another casualty of illegality.) The production of cocaine and opium is probably about the same as it was a decade ago; that of cannabis is higher. Consumption of cocaine has declined gradually in the United States from its peak in the early 1980s, but the path is uneven (it remains higher than in the mid-1990s), and it is rising in many places, including Europe.
This is not for want of effort. The United States alone spends some $40 billion each year on trying to eliminate the supply of drugs. It arrests 1.5m of its citizens each year for drug offences, locking up half a million of them; tougher drug laws are the main reason why one in five black American men spend some time behind bars. In the developing world blood is being shed at an astonishing rate. In Mexico more than 800 policemen and soldiers have been killed since December 2006 (and the annual overall death toll is running at over 6,000). This week yet another leader of a troubled drug-ridden country — Guinea Bissau — was assassinated.
Yet prohibition itself vitiates the efforts of the drug warriors. The price of an illegal substance is determined more by the cost of distribution than of production. Take cocaine: the mark-up between coca field and consumer is more than a hundredfold. Even if dumping weedkiller on the crops of peasant farmers quadruples the local price of coca leaves, this tends to have little impact on the street price, which is set mainly by the risk of getting cocaine into Europe or the United States.
Nowadays the drug warriors claim to seize close to half of all the cocaine that is produced. The street price in the United States does seem to have risen, and the purity seems to have fallen, over the past year. But it is not clear that drug demand drops when prices rise. On the other hand, there is plenty of evidence that the drug business quickly adapts to market disruption. At best, effective repression merely forces it to shift production sites. Thus opium has moved from Turkey and Thailand to Myanmar and southern Afghanistan, where it undermines the West’s efforts to defeat the Taliban.
Indeed, far from reducing crime, prohibition has fostered gangsterism on a scale that the world has never seen before. According to the UN’s perhaps inflated estimate, the illegal drug industry is worth some $320 billion a year. In the West it makes criminals of otherwise law-abiding citizens (the current American president could easily have ended up in prison for his youthful experiments with “blow”). It also makes drugs more dangerous: addicts buy heavily adulterated cocaine and heroin; many use dirty needles to inject themselves, spreading HIV; the wretches who succumb to “crack” or “meth” are outside the law, with only their pushers to “treat” them. But it is countries in the emerging world that pay most of the price. Even a relatively developed democracy such as Mexico now finds itself in a life-or-death struggle against gangsters. American officials, including a former drug tsar, have publicly worried about having a “narco state” as their neighbour.
The failure of the drug war has led a few of its braver generals, especially from Europe and Latin America, to suggest shifting the focus from locking up people to public health and “harm reduction” (such as encouraging addicts to use clean needles). This approach would put more emphasis on public education and the treatment of addicts, and less on the harassment of peasants who grow coca and the punishment of consumers of “soft” drugs for personal use. That would be a step in the right direction. But it is unlikely to be adequately funded, and it does nothing to take organised crime out of the picture.
Legalisation would not only drive away the gangsters; it would transform drugs from a law-and-order problem into a public-health problem, which is how they ought to be treated. Governments would tax and regulate the drug trade, and use the funds raised (and the billions saved on law-enforcement) to educate the public about the risks of drug-taking and to treat addiction. The sale of drugs to minors should remain banned. Different drugs would command different levels of taxation and regulation. This system would be fiddly and imperfect, requiring constant monitoring and hard-to-measure trade-offs. Post-tax prices should be set at a level that would strike a balance between damping down use on the one hand, and discouraging a black market and the desperate acts of theft and prostitution to which addicts now resort to feed their habits.
Selling even this flawed system to people in producer countries, where organised crime is the central political issue, is fairly easy. The tough part comes in the consumer countries, where addiction is the main political battle. Plenty of American parents might accept that legalisation would be the right answer for the people of Latin America, Asia and Africa; they might even see its usefulness in the fight against terrorism. But their immediate fear would be for their own children.
That fear is based in large part on the presumption that more people would take drugs under a legal regime. That presumption may be wrong. There is no correlation between the harshness of drug laws and the incidence of drug-taking: citizens living under tough regimes (notably America but also Britain) take more drugs, not fewer. Embarrassed drug warriors blame this on alleged cultural differences, but even in fairly similar countries tough rules make little difference to the number of addicts: harsh Sweden and more liberal Norway have precisely the same addiction rates. Legalisation might reduce both supply (pushers by definition push) and demand (part of that dangerous thrill would go). Nobody knows for certain. But it is hard to argue that sales of any product that is made cheaper, safer and more widely available would fall. Any honest proponent of legalisation would be wise to assume that drug-taking as a whole would rise.
The Economist first argued for drug legalization — pardon, legalisation — 
For years we have all known what Shakespeare looked like, because a copy of Martin Droeshout’s engraving of him appeared in just about every copy of the bard’s works — but that engraving was from seven years after Shakespeare’s death, when his First Folio was published.