Most recently, Uruguay took the boldest steps in this direction by legalizing production, sale, and use; along with a system of licensing and taxation that encourages individual freedom, while regulating large producers.
Taking the drug industry away from the criminals throws them out of work, so there will be increased violence as the warlords lose power. We should all work together to curb that, since we already have the resources from the drug war we're in now. The smart ones will diversify into legitimate enterprises faster than the Corleones did in the Godfather trilogy. Suddenly, there will be money flowing into the economy that had previously been kept hidden. No more drug lords - no more oppressed families losing their children to drug army gangs, so they can stay home and live productive lives in peace.