Uruguay's Senate has approved the world's first national marketplace for legal marijuana - an audacious and risky experiment that puts the government in charge of growing, selling and using a drug that is illegal almost everywhere else.
The vote was 16 to 13, with the governing Broad Front majority united in favour. The plan awaits the signature of president Jose Mujica, who wants the market to begin operating next year.
Two-thirds of Uruguayans oppose a government-run marijuana industry, according to opinion polls, but Mr Mujica said he is convinced the global drug war is a failure and feels bureaucrats can do a better job of containing addictions and beating organised crime than police, soldiers and prison guards.
"Today is a historic day. Many countries of Latin America, and many governments, will take this law as an example," said senator Constanza Moreira, voting with the Broad Front majority.
Uruguay's drug control agency will have 120 days to draft regulations imposing state control over the entire market for marijuana, from seed to smoke.
Everyone involved must be licensed and registered, with government monitors enforcing limits such as the 40 grams a month any adult will be able to buy at pharmacies for any reason or the six marijuana plants that licence-holders will be allowed to grow at home.
Congress's lower house approved the bill in late July, and senators rejected all proposed amendments, enforcing party discipline before the debate to assure the outcome.
Former health minister Alfredo Solari, a Colorado Party senator, warned that children and adolescents would more easily get their hands on pot and that "the effects of this policy on public health will be terrible".
But senator Roberto Conde, a former deputy foreign minister with the Broad Front, said marijuana "is already established in Uruguay. It's a drug that is already seen as very low risk and enormously easy to get".
Mr Mujica, a 78-year-old former leftist guerrilla who spent years in jail while many others experimented with marijuana, said the goal is to reduce drug use. A government ad campaign makes the same point, warning of pot smoking's dangers to human health.
"This is not liberalisation of marijuana. It can be consumed within certain parameters established by law. I think it will reduce consumption," senator Luis Gallo, a retired doctor who favoured the bill, said.
The government got help from a national TV campaign and other lobbying efforts supporting by billionaire currency speculator and philanthropist George Soros and his Open Society Foundation and Drug Policy Alliance. In September, Mr Mujica met Mr Soros and billionaire David Rockefeller in New York to explain his "experiment".
"I would say to Mr Soros, to Mr Rockefeller and to the president of the republic that you don't experiment with the Uruguayans. We are not guinea pigs," Colorado Party senator. Pedro Bordaberry said.