On the weekend, at the Summit of the Americas, Prime Minister Stephen Harper expressed doubt about the war on drugs. "I think what everybody believes and agrees with, and to be frank myself, is that the current approach is not working, but it is not clear what we should do."

It's admirable for a politician to admit uncertainty. And rare. Especially for a politician who has never expressed anything less than unshakable conviction in the Reaganite nostrums of drug prohibition. But Harper had good reason to be a little shaken.

The summit was held in Cartagena, Colombia, and the host, Colombian president Juan Manuel Santos, put the war on drugs at the top of the agenda. It was the only topic of discussion at the final meeting. And although we don't know in detail what was said - it was a closed-door discussion - the broad outlines are clear.

The war on drugs isn't working. Santos and other Latin American leader have said so, in public, repeatedly. Drug production is suppressed in one country so it surges in another. Trade routes are cut off so more are created. Kingpins are jailed or killed and dozens of would-be kingpins open fire - precisely the sort of "success" that has created more than 50,000 corpses in Mexico since 2006.

And all the while, corruption rots institutions from within as traffickers give politicians, judges, and police officers the awful choice of "silver or lead."

And for what? The standard metrics for measuring success are price and purity: When drug supply is successfully restricted, the price of drugs goes up while the purity goes down. But over the last 30 years - as Canada and other nations poured literally hundreds of billions of dollars into suppression, interdiction, and enforcement - the price of cocaine and other illicit drugs plummeted while purity soared.

In 1998, the world's leaders gathered for a United Nations General Assembly Special Session, at which they pledged to "eliminate or significantly reduce" the production of illicit drugs by 2008. "There are naysayers who believe a global fight against illegal drugs is unwinnable," said the UN's top drug cop. "I say emphatically they are wrong." By 2008, illicit drug production was bigger than ever.

But even that doesn't capture the full scale of the failure. Consider that in 1971, the year U.S. president Richard Nixon coined the term "war on drugs," the vast majority of Canadians and Americans had never seen or smelled marijuana, let alone smoked it, and only a determined effort could locate drugs like heroin and cocaine in shady parts of a few major cities. Today, after 41 years of global war, the illicit drug trade's distribution and retail network puts FedEx and Walmart to shame.

In Latin America, where "war on drugs" is not a metaphor, a leader would have to be completely ignorant to think the current approach is anything but a catastrophic failure. But only retired officials said so in the past.

The former president of Colombia. The former president of Brazil. The former secretary general of the United Nations (Javier Pérez de Cuéllar, a Peruvian). Current officials never seriously questioned the status quo. They couldn't. The U.S. government would blackball them if they did.

The fact that Santos and others are speaking out is a historic change. So far, the United States has been respectful, with President Barack Obama saying that while he opposes legalization it's a legitimate discussion to have.

Something has changed. And Santos has caught the moment perfectly.

At the Summit of the Americas, Santos got the leaders to ask the Organization of American States to undertake a comprehensive review of drug policies and options for change. The outcome of that review, a Santos adviser told the Guardian, "could mean anything from blanket legalization to a new and different war on drugs. We just do not know until we have the data, investigate every option with open minds, and have the full picture drawn up by experts who know the terrain, and are not motivated by interest, ideology, or emotion. Whatever it is, it must be real change, based upon new paradigms."

That review may not sound like much but it could be a big deal if done right.

As crazy as it sounds, governments have poured spectacular amounts of money into drug prohibition with little or no analysis of what good it's doing. That was the basic conclusion of a 2001 National Academy of Sciences report that looked at the $30 billion a year the U.S. was spending.

A report the same year from Canada's auditor general was even more scathing. The federal government didn't have defined goals, or any way to determine if they were being met. It didn't even know how much it was spending. (The AG guesstimated the federal government alone spent half a billion dollars a year. The provinces and cities spent much more, although how much more "is not known.")

The word that best sums up the whole mess cannot be printed in this newspaper. Let's just say that this is, as the British might put it, a cock-up of colossal proportions.

And let's not fool ourselves into thinking that we have seriously discussed this. We haven't. Marijuana decriminalization is a worthy subject but it's trivial in the big scheme. Same with supervised injection sites and the one or two other drug-related items that have received some media attention and political debate.

In reality, drug policy is enormously complex and entangled with major problems - organized crime, terrorism, insurgency, corruption, disease, social deprivation, inequality - that span the globe. It also has a long history that few people know, which explains why so many politicians propose "changes" that are actually very old ideas that failed in the forgotten past.

Colombia's president has the right idea. We must, first, accept that the status quo is a mess. That doesn't mean committing to any particular change. It just means acknowledging what is obviously true.

Then we need research. We need the history of how we got here. We need myths to be swept away. We need the essential statistics and the best available research. And then we need to lay out the options for change.

Drug policy is routinely presented as a choice between the war on drugs and corner stores selling heroin to kids. That's nonsense. There is a vast array of regulatory options between these two extremes. We need to lay them out.

With luck, the OAS report will do all that. But even if it does it will be missing much of what Canadians need to know.

Which is why we need our own royal commission.

Yes, we had the Le Dain Commission of 1972. But that was before AIDS and globalization and the modern war on drugs. It was another world.

We need a royal commission. Tom Mulcair is in favour. And the prime minister? If what he said was sincere, he should be, too.

And act accordingly.