Legalizing drugs is the best way to combat cartels, according to Vicente Fox, the former president of Mexico. Mexico's Senate is expected to vote in favor of a bill to legalize the recreational use of marijuana in the coming days, in a bid to choke off a black market dominated by violent gangs. Several Mexican Senate committees tabled draft legislation on Thursday to make the commercial production and sale of marijuana legal, expanding on a Supreme Court decision last year which deemed the country's ban on personal cannabis consumption and cultivation unconstitutional. Current President Andrés Manuel López Obrador has also been critical of Mexico's protracted drug war and signaled openness to a new approach.

Since leaving office in late 2006, Fox has been a vocal advocate for the legalization of medicinal and recreational marijuana, and last year joined the board of Canadian cannabis company Khiron Life Sciences. Speaking to CNBC in London last week, Fox pointed to Colombia, parts of the U.S. and Canada as examples where relaxing the government stance on personal recreational drug use had yielded promising results. "Watching that example, we see that in a natural way, the old illegal underground activities start to disappear by themselves, because now they don't have a market. The market is taken by the new situation — the new products, the new corporations being provided," he said. "If you go to Washington state, or Seattle, you see today that many of the old places that we used to look that were underground providing product to consumers, now they have formed part of the new industry that is legal. Now, instead of committing crimes by distributing drugs, now they do it as a businessman." Fox added that for such transitions to work, it is important that the government does not go after distributors for past illegalities, and instead enable them to legitimize their operations instead of being forced to diversify into other criminal activities.