Uruguay this week became the first country to legalize the cultivation, sale, and consumption of marijuana as part of a controversial plan to combat drug trafficking and cartels. As BBC News reports, the legislation was passed in the Senate late Tuesday after nearly 12 hours of debate. Uruguay's lower house passed the bill earlier this year, and President José Mujica — an outspoken supporter of the legislation — is expected to sign it into law.

Under the law, Uruguayans over the age of 18 will be able to purchase up to 40 grams (1.4 ounces) of marijuana per month, while licensed growers will be limited to six plants per household. It's not clear when the law will go into force, though the country's drug control agency has until April to draft a comprehensive plan to regulate the industry. Growers, sellers, and buyers will have to be registered and licensed, while public health officials have already launched a campaign to raise awareness about the drug's side effects and potential dangers.

"This is not liberalization of marijuana."

Mujica and his supporters have touted the legislation as a common-sense approach to drug reform, arguing that a tightly controlled drug market would be a more effective means of deterring cartel activities. But the initiative has faced strong opposition in Uruguay; it passed on Tuesday by a tight vote of 16 to 13 and is opposed by two-thirds of Uruguayans, according to a recent opinion poll. Speaking to BBC News, opposition member Alfredo Solari described the measure as a "social engineering experiment" that "respects none of the ethic safeguards of experimentation on human beings."

Yet the law's passage was greeted by cheers from the hundreds of people who gathered outside the Congress in Montevideo yesterday, with Senator Constanza Moreira describing it as "an historic day" and predicting that other Latin American countries will follow Uruguay's lead.

"This is not liberalization of marijuana," Senator Luis Gallo, one of the bill's supporters, told the Associated Press. "It can be consumed within certain parameters established by law. I think it will reduce consumption."