The Lancet has generally been regarded as the world's leading medical journal for more than a century.
It has been unequiviocal in it's support for legal marijuana since 1995.
The essential question is whether to believe them or the politicians.
The essential problem is a flow of information to the public that is so poor that few even know there is a major dispute between them and why.
THE LANCET, Volume 346, Number 8985, November 11, 1995
The smoking of cannabis, even long term, is not harmful to health. Yet this widely used substance is illegal just about everywhere. There have been numerous calls over the years for the legalisation or at least decriminalisation, of soft drugs, among which cannabis remains the most popular with all social groups. In this highly contentious area, the Dutch attitude has often been mentioned as the voice of sanity. In the Netherlands, customers of coffee shops can buy up to 30 g of cannabis for about the equivalent of $15, although the drug is technically illegal. The shops are not allowed to advertise, or to sell cannabis to individuals aged under 16 years.
Prominent among those currently calling for legislative reform -- and going further by making constructive proposals -- are police chiefs and city medical officers, people who know only too well that the existing policies in most countries are ineffective and unworkable. Meanwhile, politicians have largely remained silent, seemingly afraid of offending powerful segments of the electorate or merely of being perceived as weak in the face of rising crime figures. When the occasional politician raises her head above the parapet -- as the British opposition MP Clare Short did recently in calling for a fresh debate on decriminalisation of cannabis -- the response is tediously predictable: widespread condemnation from political colleagues and overwhelming support from those who have to cope with the end result of political inertia....
According to a Home Office report earlier this year, the number of people taking cannabis had doubled in a decade -- without any help from "liberal measures". Perhaps the politicians' real fear was that freedom to use soft drugs would automatically progress to increased use of substances such as cocaine and heroin. If so, they must have overlooked the recent Dutch government review which pointed out that decriminalization of possession of soft drugs had not led to a rise in the use of hard drugs. ...
Leaving politics aside, where is the harm in decriminalising cannabis? There is none to the health of consumers, and the criminal fraternity who depend for their succor on prohibition would hate it. But decriminalisation of possession does not go far enough in our view. That has to be accompanied by controls on source, distribution, and advertising, much as happens with tobacco. A system, in fact remarkably close to the existing one in Dutch coffee shops.
Cannabis has become a political football, and one that governments continually duck. Like footballs, however, it bounces back. Sooner or later politicians will have to stop running scared and address the evidence: cannabis per se is not a hazard to society but driving it further underground may well be.
Another leading medical journal has taken a similar position:
British Medical Journal, 23-30 Dec. 1996
THE WAR ON DRUGS PROHIBITION ISN'T WORKING -- SOME LEGALISATION WILL HELP
Governments worldwide have followed illogical and often counterproductive drug policies, primarily because drug use is seen in moral terms. Wars on drugs are doomed to failure, but experiments with decriminalising and even legalising drugs -- as in the Netherlands -- have shown promising results.
Policies that allow some decriminalisation and legalisation are much more likely than prohibition to succeed in achieving everybody's aim of minimising the harm from drug abuse.