Mexican drug cartels already control the bulk of cocaine, marijuana and heroin that enters the United States and are now fast becoming the kings of methamphetamine

Once the province of domestic drug makers, much of the methamphetamine coursing through the United States now originates in Mexico. Through the first half of 2011, Mexico’s military found 103 meth labs, 25% more than in 2010, when a record 6.2 tons of the synthetic drug were seized at the US border. Already in 2011, authorities have seized nearly that much. Though the number of US meth labs is rising, 96% of those busted in 2010 couldn't produce more than two ounces of the drug — just enough for personal use, leaving mass production to Mexico. In recent weeks, Mexican authorities discovered a warehouse holding 839 tons of meth and ecstasy ingredients. With a gram of meth going for some $100, hundreds of millions of dollars could be at stake. Half a million Americans are believed to be users and synthetic drugs, notes a Mexican official, can be produced in only a few hours with higher dividends, unlike marijuana whose harvest takes months and requires more manpower.