BEFORE “Breaking Bad”, there was “Miami Vice”. The 1980s television show pitted detectives in white linen suits against drugs traffickers who used the Caribbean as their point of entry into Florida. The route, at least, is back in fashion. The proportion of cocaine imports entering the United States via the islands is rising (see article), as clampdowns in Central America and Mexico push drugs gangs back to their old haunts.

The revival in Caribbean drugs traffic is just the latest example of the “balloon effect”, in which squashing down on illicit activity in one place causes it to pop up somewhere else. Colombia’s war on drugs in the 1990s and 2000s is another: coca crops moved back to Bolivia and Peru, now the world’s biggest grower; cocaine-processing shifted next door, to Ecuador and Venezuela; Mexico’s drugs gangs grabbed market share. A subsequent bloody clampdown on Mexican gangs diverted traffickers to Central America: Honduras became the region’s largest entry point for airborne smugglers. With the shift back to the Caribbean, the trade has come full circle.

The balloon effect also operates among consumers. Cocaine and heroin usage is dropping in places like the United States and Britain, partly because of educational campaigns, partly because of falling levels of purity (cocaine in Europe, for example, is often adulterated with a cattle-worming drug). But consumption of synthetic drugs like methamphetamine, ketamine and mephedrone is rising to compensate, in both developing and developed countries. Seizures of methamphetamines have tripled in Asia in the past five years. New ways of getting high proliferate faster than the authorities can keep tabs on. A report from the UN Office on Drugs and Crime says that 348 new psychoactive substances have been reported to the agency, most of them since 2008 (see article).

Prohibitionist drugs policies do have an effect. Traffickers are being inconvenienced; prices are raised. But the war on drugs surely aimed higher than merely altering the stuff people that take and how they get hold of it. It cannot count as a success if global consumption of illicit substances is going up, not down.

Worse, the spillovers can be grave. Attacking gangs in one country does not just increase bloodshed there, it also exports violence abroad. Seizures of drugs create scarcity further down the supply chain, giving traffickers a greater incentive to use force. Researchers have estimated that Colombian interdiction policies may explain as much as half of the increase in drug-related homicides in Mexico between 2006 and 2010. The extraordinary homicide rates in Central America—Honduras is the world’s most murder-prone country—partly reflect the influx of narco-traffickers after Mexico’s own crackdown. Once the gangs arrive, they are hard to dislodge entirely; the side effects, like corruption and extra weapons, outlast them.

Consumer countries suffer, too. No one yet understands the long-term health effects of the new psychoactive substances that people hoover up, but some synthetic cannabinoids are clearly more dangerous than farmed marijuana. And production is more mobile, which means that the violence associated with supplying drugs is creeping closer to sources of demand. Meth labs are being discovered in the United States and Europe on a daily basis.

Circular logic

This newspaper’s views on drugs are well known. Legalisation is the best way to prevent harm to users, and to shove the gangs aside. To work, prohibition requires an almost impossible sustained level of international co-operation and resourcing. The drugs war needs a rethink, not endless repeats.