Will Mexico's drug cartels see a drop in profits as a result of changes in the US?
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Earlier this month, two US states voted to legalise, regulate and tax marijuana. The BBC's Will Grant in Mexico City looks at what this shift in stance could mean for Mexico and its fight against the drug gangs.
Every year, pro-marijuana campaigners in Seattle hold their annual Hempfest, a two-day festival along the city's shoreline.
Thick pungent clouds of pot smoke waft over the crowd who are sitting out with a joint in their hand, listening to the live music, or pottering among the dozens of stalls selling bongs, pipes and other smoking paraphernalia.
The police are on hand to ensure there is no open buying or selling of the drug. But at the next 'Hempfest', they may not even need to do that.
On the day voters in Washington state chose to re-elect President Barack Obama, they also chose to legalise the recreational use of marijuana. Over the Rockies in Colorado, it was a similar story.
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What has happened in the US has moved things forward, because this debate is crucial”
Fernando Belauzaran
Mexican politician
Burning questions about legal pot
Uruguay bill to legalise drug use
"What happened in Colorado and Washington was truly revolutionary," says Beau Kilmer, the co-director of the Rand Drug Policy Research Centre in California. "No modern country has ever removed the prohibition on the production and distribution of marijuana for non-medical purposes."
When the measure comes into effect in Colorado in early December, it will be legal to possess 1oz (28g) of marijuana if you are over 21; it will be legal to grow up to six marijuana plants in your house; and it will be legal to give away up to 1oz.
There are still complex questions about creating a regulatory framework for the production and distribution of the drug, which may take at least another year.
Needless to say, such a move puts the two states on a legal collision course with the federal government and its drug enforcement policies. But Dr Kilmer believes it is a mistake to view the Obama administration as a single entity in this regard.
"At this point no-one knows how the federal government is going to respond to these two states. But it's important that we don't think of it as a homogenous actor.