The Washington Post reports:
Mexico's Congress opened a three-day debate Monday on the merits of legalizing marijuana for personal use, a policy backed by three former Latin American presidents who warned that a crackdown on drug cartels is not working.
... three former presidents _ Cesar Gaviria of Colombia, Ernesto Zedillo of Mexico and Fernando Cardoso of Brazil _ urged Latin American countries to consider legalizing the drug to undermine a major source of income for cartels.
As as another article in the Post reported California is also considering legislation to legalize marijuana:
...in California, pot is such a booming growth industry that lawmakers are being asked to consider its potential as a salve to the state's financial woes. Betty Yee, chairman of the California State Board of Equalization, citing the state's budget problems. California currently collects $18 million in sales taxes from marijuana dispensaries, and [chairman of the California State Board of Equalization Betty] Yee said a regulated pot trade would bring in $1.3 billion.
Prohibition doesn't kill demand it only enriches the criminal class - and the insurgents in Afghanistan's case.