Two years ago, Border Patrol agents began to voice what many believed were legitimate concerns about "armed incursions" into the United States from Mexico-based assailants. Now these invasions occur routinely putting federal agents' and law enforcement officers' lives in jeopardy. They reported that heavily armed Mexican army units and federal police, called federales, had infiltrated US territory and fired upon them, in some cases because –- federal agents would later discover –- Mexican drug lords had put prices on the heads of American law-enforcement agents strung out along the border. Where was the outrage by our political leaders and the...