Mexico also is the top foreign supplier of marijuana and methamphetamine . Sinaloa , Gulf cartels battle for control of drug routes across U.S. border . The turf war has spurred record death tolls with gunbattles , beheadings . U.S. is doubling number of agents at border , spending $ 700 million . Comment:
Sinaloa , Gulf cartels battle for control of drug routes across U.S. border . The turf war has spurred record death tolls with gunbattles , beheadings . U.S. is doubling number of agents at border , spending $ 700 million . Comment: