 Methamphetamine and cannabis production do take place in Mexico and are responsible for an estimated 80% of the methamphetamine on the streets in the United States, while 1,100 metric tons of marijuana are smuggled each year from Mexico.In 1990 just over half the cocaine imported into the U.S. came through Mexico, by 2007 that had risen to more than 90 percent, according to U.S. State Department estimates.Although violence between drug cartels has been occurring long before the war began, the government used its police forces in the 1990s and early first decade of the 21st century with little effect.