UNDER ATTACK: FOX NEEDS FIRM ALLY IN DRUG WAR Accounts of violence in Mexico sound like they come from the war zone in Iraq, not from Texas' border region. Armed men appear from nowhere and kidnap six prison workers, including three guards. The captives are blindfolded and handcuffed, then assassinated with gunshots to the head - the latest bloody episode in a reign of terror aimed at shaking the government. This scenario unfolded last week a short distance from Texas soil, in Matamoros, Mexico, in a chilling message to Mexican federal authorities from top drug lords. Mexican President Vincente Fox is being challenged in unprecedented ways due to his aggressiveness in jailing major traffickers and his moves to disrupt their control while in prison. The United States cannot see him fail, lest we want a narco-republic to take firm root south of the Rio Grande. Mr. Fox deserves all the practical and moral support one would expect from an ally against a common enemy. Mr. Fox's response to the massacre was a reassuring and necessary show of force: Declaring "the mother of all fights," he dispatched troops to secure the Matamoros prison and a second one near Mexico City. Troops and tanks are also patrolling the border town of Reynosa in response to epidemic violence there. Reynosa's mayor held a press conference in Texas last week in a pathetic attempt to pronounce his city safe for U.S. shoppers - mostly the tens of thousands of retirees who flood South Texas this time of year. In light of kidnappings of several Texans, U.S. consular officials have issued warnings about crossing into Mexico. As border life deteriorates for both countries, the United States can send a stronger signal - that Mr. Fox does not stand alone against the drug lords. The U.S. government has a history of offering logistical support to Mexican law enforcement, such as large numbers of FBI agents who helped investigate mass murders in Ciudad Juarez. A similar show of solidarity is called for now, as Mr. Fox engages a direct threat to rule of law in his country.