As protests and gunfire erupted last week across Reynosa, Hidalgo County authorities stood prepared at the international bridges, ready for any possibility.
With mobile command units connected to statewide intelligence centers and dozens of officers armed to confront potential threats, law enforcement officials responded to Tuesday's violence like they never have before.
The incident prompted state officials to enact for the first time a border-wide emergency plan developed to address threats from Mexico's ongoing war against its entrenched drug cartels.
Dubbed the "Operation Border Star Contingency Plan," Gov. Rick Perry's office drafted the policy with local, state and federal law enforcement agencies last year to prepare for the possibility of violence spilling over into the United States.
"The most significant threat Texas faces is spillover violence from Mexico's drug cartels," Perry's homeland security director, Steve McCraw, told state senators at a hearing Wednesday. "You can never be too prepared."
Last year, more than 5,700 Mexican citizens died as a result of drug-related violence, according to estimates by the country's attorney general's office. Some 260 more have been killed in cities such as Ciudad Juarez just in the first two months of this year.
And as Mexican President Felipe Calderon continues his administration's three-year crackdown on the nation's crime syndicates, those numbers are only expected to rise.
Texas has yet to see widespread outbreaks of open drug violence on this side of the border, but its status as a primary smuggling corridor makes it vulnerable to potential attacks, state officials said.
"These groups don't care about boundaries," McCraw said. "They don't care about how we organize ourselves."
The protests Tuesday at border crossings in cities such as Reynosa, Nuevo Laredo and Ciudad Juarez drew thousands of demonstrators but remained relatively calm. A separate Mexican army raid on a suspected Gulf Cartel safe house led to a shootout that killed at least six later that day.
The violence remained confined to the Mexican side of the border, but the incident provided a good test run for the lowest levels of the Border Star contingency plan, said Katherine Cesinger, a spokeswoman for the governor.
"We're doing what we can to fill in the gaps from a state level," she said.
Throughout the day, a central operations center in Austin sent constant intelligence updates to state, local and federal law enforcement agencies up and down the border. They kept in constant contact over a designated radio band as the situation developed.
That state of heightened alert makes up the lowest level of response outlined in the security plan. While individual response policies have been developed for five border regions across the state and Texas' coastal bend, officials remained tight-lipped regarding many of the specifics, citing security concerns.
But local law enforcement officials who helped develop the plans say they address several potential scenarios ranging from violence close to the Texas border to sustained attacks on U.S. citizens and law enforcement in Texas.
At each increasing threat level, different local, state and federal authorities will be called in to establish order, they said. In the direst situations, the governor could dispatch the Texas Army National Guard to help maintain the peace.
"There's no doubt that there's been a slight extension - not a spillover - of (drug) violence into Hidalgo County so far," Sheriff Lupe Treviño said. "But we have to be prepared for more serious situations."
THREAT OF COLLAPSE?
So far, the plan addresses law enforcement concerns only, state officials said. It does not provide for other possibilities such as effects on the local economy or increased levels of refugees and asylum seekers.
But those are all scenarios that should be considered, said Cameron County Judge Carlos Cascos, who also helms the governor's Border Security Council.
"You are already seeing the beginning stages of that now," he said. "Some of the wealthy and upper-middle-class Mexicans are buying second or third homes here because they are concerned about the state of their country."
The U.S. Department of Defense went even further late last year when it issued a report that listed Pakistan and Mexico as countries whose governments face a threat of rapid collapse.
Based in part on the report's recommendation, the then U.S. Homeland Security secretary, Michael Chertoff, ordered his agency to begin preparing its own border spillover contingency plan. But like its state equivalent, the details have been kept under wraps.
While state and local officials have called a full-scale government collapse unlikely, Cascos predicts the security situation along Texas' southern frontier will only continue to deteriorate.
"Until Mexico gets a handle on the activities going on over there," he said, "these problems are going to continue making their way to this side."
Jeremy Roebuck covers courts and general assignments for The Monitor. You can reach him at (956) 683-4437.