MEXICO CITY -- As drug violence spirals out of control in Mexico, a commission led by three former Latin American heads of state blasted the U.S.-led drug war as a failure that is pushing Latin American societies to the breaking point.

"The available evidence indicates that the war on drugs is a failed war," said former Brazilian President Fernando Henrique Cardoso, in a conference call with reporters from Rio de Janeiro. "We have to move from this approach to another one."

The commission, headed by Mr. Cardoso and former presidents Ernesto Zedillo of Mexico and César Gaviria of Colombia, says Latin American governments as well as the U.S. must break what they say is a policy "taboo" and re-examine U.S.-inspired antidrugs efforts. The panel recommends that governments consider measures including decriminalizing the use of marijuana.

The report, by the Latin American Commission on Drugs and Democracy, is the latest to question the U.S.'s emphasis on punitive measures to deal with illegal drug use and the criminal violence that accompanies it. A recent Brookings Institution study concluded that despite interdiction and eradication efforts, the world's governments haven't been able to significantly decrease the supply of drugs, while punitive methods haven't succeeded in lowering drug use.

John Walters, former director of the White House Office of National Drug Control Policy, said, "It's not true that we've lost or can't do anything about the drug problem," and cited security improvements in Colombia.