“But what if Juárez is not a failure? What if it is closer to the future that
beckons all of us from our safe streets
and Internet cocoons?”
—Charles Bowden, Murder City
On September 30, 2010, David Hartley and his wife, Tiffany, were jet-skiing on Falcon Lake along the Texas-Mexico border when a speedboat approached them and several men on board opened fire, killing Mr. Hartley. The “pirates” who attacked the Hartleys were most likely members of Los Zetas, a group of former Mexican special-forces troops who had defected to act as enforcers for one of the leading Mexican drug cartels before going into business for themselves. This was but one of a series of attacks on Americans and other incursions into U.S. territory in recent years by heavily armed, militarized units connected to the cartels, probably including Mexican army troops, some of whom have at times cleared the way for drug traffickers. In March of that same year, Robert Krenz, an Arizona rancher, was murdered, likely by traffickers using his property as a transit route for shipments of narcotics. Meanwhile, American law-enforcement officers noted the expansion of the cartels into cities like Atlanta, far from the Mexican border.
As Mexican drug violence was “spilling over” into the United...