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Last week, Mexico’s President Calderon called on President Obama to join the debate on legalizing marijuana. The US drug policy has lined the pockets of the drug cartels with billions of dollars, and they are threatening to destabilize not only Mexico but countries across Latin America.

In many regions, the drug gangs are seeking to replace the government, imposing their own taxes in towns they dominate.

Three former Latin American presidents — Cesar Gaviria of Colombia, Ernesto Zedillo of Mexico and Fernando Cardoso of Brazil — wrote an oped in the Wall Street Journal, urging the legalization of marijuana as a way to undermine a major source of income for cartels.

Recently, the U.S. Joint Forces Command warned that the Mexican government could experience “a rapid and sudden collapse” due to drug cartel violence.  And the outgoing head of the CIA, Gen. Michael Hayden, warned that drug cartels “threaten … the well-being of the Mexican people and the Mexican state.”

The problem is so bad that following President Calderon’s statement, two Mexican cardinals have endorsed his call to open a debate on the merits of  legalization.

There have been 28,000 people killed since 2006 in the war with the drug cartels,  including 1200 in July –  the deadliest month yet.  The recent shooting in Arizona that triggered the debate between right and left over immigration was the result of marijuana smuggling, not people trying to get over the border to find jobs.  It’s insane that the conversation instantly devolved into a right-left battle over immigration.  The Arizona law does nothing to address the underlying problem.

Yesterday the Guardian had a piece on the push to end prohibition, including the Just Say Now campaign we launched last week.  Further,  the Guardian editorial board called on David Cameron and Nick Clegg to “launch a national debate on whether we should try legalisation,” and to “tear up the current policy. It has failed.”  “That debate must be opened in Britain and the recent change of government provides a rare opportunity,” they say.

But as Peter Guither notes, although there is strong interest in the issue among both progressive and conservative voters, leadership on both sides of the aisle have been unwilling to address it.  Most are terrified of walking into a meat grinder of social taboos left over from the culture wars, and they won’t brave it until the public demands it.

That’s why we launched the Just Say Now campaign.  Over 30,000 people have already signed the petition to President Obama, saying it’s time to end the war on marijuana.  America’s prison population has quadrupled since 1984 when Nancy Reagan’s war on drugs began, and the private prison system exploded.

Last fall, Eric Holder issued a directive that the DEA should respect state medical marijuana laws.  But as  Jacob Sullum notes, that directive had a lot of wiggle room and as a result the DEA’s raids on medical marijuana suppliers continue.

Please show your support and sign the petition asking President Obama to end the war on marijuana.