Argentina's Supreme Court decriminalised the small-scale use of marijuana on Tuesday 25th August 2009, opening the way for a shift in the country's drug-fighting policies to focus on traffickers instead of users.
The high court ruled it unconstitutional to prosecute cases involving the private use of marijuana.
Elsewhere in Latin America, Colombia and Mexico have already decriminalised the possession of small amounts of drugs. Brazil and Ecuador are looking at an initiative to legalize some drug use.
"Each adult is free to make lifestyle decisions without the intervention of the state," the court's ruling said. It did not set a weight limit for what constitutes small-scale and the court said it was not decriminalizing all drug use.
The decision struck down a 2006 lower court ruling involving eight people sentenced to jail terms for carrying marijuana cigarettes.
"Behavior in private is legal, as long as it doesn't constitute clear danger," Supreme Court President Ricardo Lorenzetti said. "The state cannot establish morality."
Elias Neuman, a criminology professor at the University of Buenos Aires, said Tuesday's ruling "could be a step forward" in legalizing the personal use of other drugs.
"It is now clear what drug dealers do is sell people on drugs, and not the other way around," he said.
The Argentine government had urged the high court to review drug possession laws, seeking to redirect state spending on pursuing dealers and drug treatment instead of what officials called expensive prosecutions of thousands of smaller cases.
The ruling drew criticism from Argentine officials in the Roman Catholic Church and families of drug users who worry it will lead to increased drug trafficking.
A household survey showed an increase in the rate of marijuana use in Argentina. Consumption among the population aged 12 to 64 rose to 6.0 percent in 2006 from 1.9 percent in 2004, reversing a previous downward trend.
Marijuana use in Argentina is now at levels similar to those reported in western and central Europe, according to the latest United Nations World Drug Report.
Argentina, whose population is less than a quarter that of Brazil, is Latin America's biggest cocaine user, according to the U.N. report.
Several high-profile police raids and murders linked to drug gangs have exposed the country's status as a transit point for Andean cocaine bound for Europe and a source of precursor chemicals used to make drugs such as methamphetamine.