Mexican state police and army units clashed with Mexican drug cartel gunmen on Saturday in the town of Villa Union in the northeast Mexican state of Coahuila, near the Texas border town of Nueva Laredo. The resulting violence left at least 21 people dead.

The violence began when truckloads of armed gunmen, estimated between 70-150, began pouring into the town attacking the town’s municipal hall and other local offices. This attack, right on the doorstep of the United States, will serve to promote President Trump’s message of last week, that he intends to label Mexico’s drug cartels as terrorist organizations.

After the shootout that left townspeople scared and hiding, several municipal buildings and about 50 homes were riddled with bullet holes.

Government forces found 25 abandoned vehicles. Several witnesses claim that there were twice as many as the cartel poured into the town. Many of the cartel’s vehicles used welded armor plating and gun turrets and had printed placards identifying them as belonging to the cartels. At least four of them had mounted .50 caliber machine guns.

The AP was the first to report that cartel vehicles began to roll into the town at approximately 11:30 a.m. on Saturday. Residents were enjoying the weekend with many of their relatives that live on the U.S. side of the border. While people in the U.S. were enjoying their Thanksgiving, the town of Villa Union was celebrating Dia del Pavo (Turkey Day).

With the trucks and vehicles rolling into town, many residents saw the body armor and ammunition vest carriers that the truck occupants were wearing and assumed that they were army troops. However, once residents noticed that several of the trucks either had no license plates or had Texan plates, they knew they were cartel members and began to hide. Other residents saw placards with CDN printed on them. CDN (Cartel del Noreste: Northeast Cartel) is an offshoot of the Zeta cartel.

The gunmen descended from their vehicles at approximately 11:45 a.m. and began firing into the town’s municipal hall. Petrified civilians were locking doors and hiding in whatever cover they could find.

After Mexican army troops were dispatched from their barracks west of Villa Union, the gunmen split into two groups and took several locals hostage to use them as guides to navigate the streets and exfiltrate from the town. At least two of the hostages were later found dead.

A half-hour later, cartel gunmen ran headlong into army and state police units on the outside of town near a gas station. There a pitched shootout began that resulted in four police officers and at least nine gunmen being killed.

The cartel members tried to flee toward Nueva Laredo, but the army and state police units were using helicopters in scouring the surrounding area and hunting them down. Seven more cartel members were killed during the later afternoon and evening.

On Sunday, the army rushed troops into Villa Union to restore calm and sift through the remnants of the fighting for intelligence.

Many people, on both sides of the border, now fear that this latest violence will only fuel Trump’s desire to use military force against the cartels — with or without authorization from the Mexican government.

And that authorization isn’t coming. Mexicans have a built-in abhorrence of armed U.S. troops carrying out operations on Mexican soil. The Mexican president, Andrés Manuel López Obrador, has already stated that he doesn’t want U.S. troops in Mexico fighting the cartels.

“Since 1914, there hasn’t been a foreign intervention in Mexico and we cannot permit that,” López Obrador said on Friday. “Armed foreigners cannot intervene in our territory.”

But violence is rising despite López Obrador’s policy of “Brazos no balas” or “Hugs not bullets” in dealing with the cartels. Homicides relating to cartel violence have been nearly 30,000 in 2019. And there doesn’t appear to be any end in sight.

In labelling the drug cartels terror organizations, the U.S. government can sanction groups, who do business with or support the cartels, extradite cartel members to the United States and ban any known-associates from entering the country. But most importantly, it could open the path for President Trump to bring to bear military force against cartel members and operations.

U.S. Attorney General William Barr is visiting Mexico next week for an already scheduled trip to discuss joint security operations. It is expected that he’ll push for greater cooperation between the two countries.

López Obrador knows that allowing any U.S. military operation on Mexican soil would end his political career and likely ignite even more violence. While the U.S. and Mexico already share many joint efforts from across the border, it is quite different to allowing U.S. military units to operate in Mexico en masse. But many expect that Trump, through Barr, will push for it.