Illegal drugs are used by 270 million people and organized crime profits from a trade with a turnover of more than $320 billion a year, according to figures from the UN Office on Drugs and Crime (UNODC). This makes it the world's largest illegal commodity market.

In 1961, the UN brought its prohibition-based regime under one instrument -- the Single Convention on Drugs, which obliged states to prohibit production, supply and use of certain named drugs. Yet most indicators suggest that drugs are now cheaper and more available than ever.

The UNODC now acknowledges that choosing an enforcement-based approach is having a range of negative 'unintended consequences'. These include the creation of a vast criminal market, the spreading of the illegal drugs trade to new areas, the stigmatization of drug users and the diversion of money from health services.

It is worthy of note though that, as well as prohibiting production, supply and use of some drugs for non-medical purposes, the UN Single Convention on Narcotic Drugs also regulates production, supply and use of many of the same drugs for medical purposes. Half the world's opium is legally grown for this medical market, but with few if any of the negative consequences that we see in the prohibited market.

It is, however, unacceptable that neither the UN nor its member governments have meaningfully assessed these 'unintended consequences' to establish whether they outweigh the 'intended consequences' of the current system.

The Alternative World Drug Report released this year on June 26, World Drug Day, demonstrates how the war on drugs wastes billions of dollars a year and undermines economies, international development and security. It also fuels conflict, threatens public health, undermines human rights, promotes stigma and discrimination creates crime and causes deforestation and pollution.

In light of this evidence, the report called upon governments to explore all the alternative options, including intensifying the war on drugs, maintaining the status quo, health-led approaches and legal state regulation and control.

This call is starting to resonate worldwide. In April, the summit of the Organization of American States, committed to conduct the first official review of all policy options in the region.

During these discussions, President Obama said: 'I think it is entirely legitimate to have a conversation about whether the laws in place are ones that are doing more harm than good in certain places.' He had earlier said that he considered legalization an 'entirely legitimate topic for debate'.

Meanwhile, Britain does not even have an evaluation framework to assess the efficacy of its current drug strategy, let alone a system to assess possible alternatives.

As the Home Affairs Select Committee finishes hearing evidence in its inquiry into UK drug policy, it is more important than ever that it calls for a comprehensive evidence- based review of all policy options. The specific frameworks for controlling currently illegal drugs under a legally regulated regime are well known and have been detailed in our book After the War on Drugs -- Blueprint for Regulation.

Fifty years ago Britain joined the rest of the world in making 'drugs' a criminal issue. In hindsight it was a gargantuan mistake. But mistakes can be rectified.

Decoupling drugs policy from crime policy would enable states to focus global enforcement efforts on organized criminals; leaving governments to choose the most appropriate drug policies for their domestic and regional needs.

This is no longer a debate for dinner parties. The Latin Americans are leading the way; it is up to us to follow.

Danny Kushlick is head of external affairs at Transform Drug Policy Foundation and a member of the Independent Advisory Panel for the Chatham House Drugs and Organized Crime Project

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