Apparently it is the 100th anniversary of the War on Drugs, not the actual slogan coined in the 1960s, but the founding of the International Opium Commission.
The Economist argues that the effort has failed and that drugs should be legalised, I am inclined to agree with them. Thankfully it avoids the utopianism associated with many advocates of legalisation.
To argue that the benefits will outweigh the costs does not mean that there won't be serious problems associated with legalising narcotics. In particular it will make drug use less costly and therefore more widespread. The people who chose to outlaw drugs a century ago didn't do it for its own sake, they were addressing a real problem, that a large proportion of the population was addling their minds on dope.
The costs of legal drugs like tobacco and alcohol are the increased rates of disease among users, addiction and in the case of alcohol an increased rate of violence. It is likely that similar effects would be seen if cannabis, ecstasy, cocaine and heroin were legal.
Having said all that, the effects of banning them are a lot worse, most of the harm caused by legal drugs is done to the users themselves, whilst it would be regrettable if more cannabis users developed schizophrenia, they have done it to themselves, however the hundreds of thousands of people gunned down in Latin America by drug cartels didn't choose to be killed. Inner city communities throughout the Western world didn't choose to have their neighbourhoods controlled by drug gangs. The children of drug addicts who contract hepatitis or Aids didn't choose to do so.
One thing I should add though is that legalisation is not the same as decriminalisation, which is a halfway house policy that encompasses the worst aspects of legalisation and criminalisation.