Mexico's government has pledged to deploy more security forces to Tamaulipas -- right on the Texas border, and one of the country's most violent states. Mexican Governance Minister Miguel Angel Osorio promised a "new phase" of action against the state's warring drug cartels.

The move was prompted by the May 5 assassination of Salvador Haro Muñoz, the Tamaulipas state government intelligence chief, in an ambush on his car in the state capital, Ciudad Victoria. Ten officers from the Tamaulipas state police force have been arrested by federal authorities in connection with the hit, which was said to have been carried out by the Zetas narco-paramilitary network. Also detained was José Manuel López Guijón, security chief for Tamaulipas Gov. Egidio Torre Cantú.

Osorio announced that the state would be divided into four regions, each with an army or navy officer in charge of implementing the government's security plan. "We will strengthen surveillance at ports, airports, customs and border crossings, as well as the major land routes," he told a press conference in the border town of Reynosa. Osorio said security forces would "patrol 24 hours, every day of the week, in main urban areas," and would conduct reviews of local police forces to eradicate corruption.

But there is a sense of ominous deja vu to all this, as the Mexican government has many times before pledged to get Tamaulipas under control with big troop deployments, and each time it has only escalated the level of violence...