The Drug Trade
"Mexico continues to experience high levels of violence as a result of illicit drug trafficking organizations and efforts to counter them. Criminal cartels—which traffic 95 percent of the cocaine consumed in the United States—have killed an estimated sixty thousand Mexican soldiers, police, politicians, and civilians since 2006.
[...] Mexican law enforcement and criminal justice institutions remain deeply corrupt, leaving Mexico vulnerable to increased violence and the expansion of cartel-controlled areas. Vigilante autodefensas, or illegal self-defense groups originating in rural areas, have attempted to compensate for ineffective local police forces, but some are concerned that these groups could become predatory forces themselves.
A deeply embattled Mexican state could undermine U.S. efforts to halt the flow of Mexican migrants and contraband across the border. Moreover, the expansion of Mexican criminal networks into Central America and the Caribbean poses a grave threat to the already fragile region."