Zetas are arguably the most violent and fearsome drug cartel group. It was the Zetas who massacred 72 migrant workers and then left their bodies rotting in a a pile outside a ranch near the U.S. border in late August..Some of the initial cartel members were elite Mexican troops and that is where the U.S. and Fort Bragg enter the picture. These Mexican troop were trained in the early 1990s by the 7th Special Forces Group or "snake eaters" at Ft. Bragg, North Carolina. Craig Deare a former special forces commando said:"They were given map reading...