The war on drugs is a lost war, and 2011 is the time to move away from a punitive approach in order to pursue a new set of policies based on public health, human rights, and commonsense. These were the core findings of the Latin American Commission on Drugs and Democracy that I convened, together with former presidents Ernesto Zedillo of Mexico and Cesar Gaviria of Colombia.

We became involved with this issue for a compelling reason: the violence and corruption associated with drug trafficking represents a major threat to democracy in our region. This sense of urgency led us to evaluate current policies and look for viable alternatives. The evidence is overwhelming. The prohibitionist approach, based on repression of production and criminalisation of consumption, has clearly failed.

After 30 years of massive effort, all prohibition has achieved is to shift areas of cultivation and drug cartels from one country to another (the so-called balloon effect). Latin America remains the world's largest exporter of cocaine and marijuana. Thousands of young people continue to lose their lives in gang wars. Drug lords rule by fear over entire communities.

We ended our report with a call for a paradigm shift. The illicit drug trade will continue as long as there is demand for drugs. Instead of sticking to failed policies that do not reduce the profitability of the drug trade - and thus its power - we must redirect our efforts to the harm caused by drugs to people and societies, and to reducing consumption.

Some kind of drug consumption has existed throughout history in the most diverse cultures. Today, drug use occurs throughout society. All kinds of people use drugs for all kinds of reasons: to relieve pain or experience pleasure, to escape reality or enhance their perception of it.

But the approach recommended in the commission's statement does not imply complacency. Drugs are harmful to health. They undermine users' decision-making capacity. Needle-sharing spreads HIV/AIDS and other diseases. Addiction can lead to financial ruin and domestic abuse, especially of children.

Cutting consumption as much as possible must, therefore, be the main goal. But this requires treating drug users not as criminals to be incarcerated, but as patients to be cared for. Several countries are pursuing policies that emphasise prevention and treatment rather than repression - and refocusing their repressive measures on fighting the real enemy: organised crime.

The crack in the global consensus around the prohibitionist approach is widening. A growing number of countries in Europe and Latin America are moving away from a purely repressive model.

Portugal and Switzerland are compelling examples of the positive impact of policies centred on prevention, treatment, and harm reduction. Both countries have decriminalised drug possession for personal use. Instead of leading to an explosion of drug consumption, as many feared, the number of people seeking treatment increased and overall drug use fell.

When the policy approach shifts from criminal repression to public health, drug users are more open to seeking treatment. Decriminalisation of consumption also reduces dealers' power to influence and control consumers' behaviour.

In our report, we recommend evaluating from a public-health standpoint - and on the basis of the most advanced medical science - the merits of decriminalising possession of cannabis for personal use.

Marijuana is by far the most widely used drug. There is a growing body of evidence suggesting that the harm it causes is at worst similar to the harm caused by alcohol or tobacco. Moreover, most of the damage associated with marijuana use - from the indiscriminate incarceration of consumers to the violence and corruption associated with the drug trade - is the result of current prohibitionist policies.

Decriminalisation of cannabis would thus be an important step forward in approaching drug use as a health problem and not as a matter for the criminal justice system.

To be credible and effective, decriminalisation must be combined with robust prevention campaigns. The steep and sustained drop in tobacco consumption in recent decades shows that public information and prevention campaigns can work when based on messages that are consistent with the experience of those whom they target. Tobacco was deglamorised, taxed, and regulated; it has not been banned.

No country has devised a comprehensive solution to the drug problem. But a solution need not require a stark choice between prohibition and legalisation. The worst prohibition is the prohibition to think. Now, at last, the taboo that prevented debate has been broken. Alternative approaches are being tested and must be carefully reviewed.

At the end of the day, the capacity of people to evaluate risks and make informed choices will be as important to regulating the use of drugs as more humane and efficient laws and policies. Yes, drugs erode people's freedom. But it is time to recognise that repressive policies towards drug users, rooted as they are in prejudice, fear, and ideology, may be no less a threat to liberty.

Fernando Henrique Cardoso, a former president of Brazil (1995-2002), is co-chairman of the Latin American Commission on Drugs and Democracy, and convener of the Global Commission on Drug Policy. Copyright: Project Syndicate, 2010.