Criminal violence has engulfed parts of Mexico after troops killed Nemesio Oseguera Cervantes, alias El Mencho, head of the mighty Jalisco New Generation Cartel. Planned with the aid of Mexican and U.S. intelligence, the operation to capture El Mencho culminated in a firefight in which seven suspects died and three soldiers were injured, according to the Army. The cartel’s response to its leader’s demise was immediate. Beginning in the group’s home state of Jalisco, combatants set cars, buses and businesses on fire, and blockaded roads. Within hours, violence spread to twenty states. In Guadalajara, Jalisco’s capital, civilians sheltered in place, businesses closed early, and the government suspended public transportation. The uprising killed at least 25 National Guardsmen and one civilian.

The Jalisco Cartel originated in the late 2000s as an armed force affiliated with the Sinaloa and Milenio cartels. As the cartel grew under his stewardship, El Mencho exercised tight control. He expanded its grip across the country, typically by either absorbing or franchising smaller outfits. Unlike many other criminal groups in Mexico, his operation was highly centralised and has shown no visible fractures since its inception. Today, it is a frontrunner in the production and trafficking of fentanyl, a highly addictive and lethal synthetic opioid, as well as extortion rackets in Mexico’s agricultural and mining regions.

Under El Mencho’s watch, the Jalisco Cartel became a major military force, showcasing its firepower in widely disseminated videos. The group includes both local recruits and foreign mercenaries, while its arsenal features high-powered sniper rifles, aerial rockets, drones, and myriad improvised explosive devices. In the crowded Mexican criminal landscape, Jalisco Cartel also stood out for its propensity for brazen violence against government officials. In June 2020, its hitmen ambushed but failed to kill Omar García Harfuch, then leading Mexico City’s fight against crime and today chief of public security for President Claudia Sheinbaum. More recently, the cartel killed a popular mayor in Michoacán.

Sunday’s operation is likely to strengthen Sheinbaum’s negotiating position in ongoing talks with U.S. President Donald Trump, who has repeatedly threatened to strike cartels on land and is said to have demanded a direct U.S. role in ground operations in Mexico. In taking out El Mencho, Sheinbaum has demonstrated that cooperation and intelligence-sharing can produce the results that Trump desires, and that Mexican troops are equipped to take down high-value targets.

But claiming a top criminal scalp will not spare the government from a messy aftermath. Federal authorities announced that they are reinforcing troop deployments to contain the cartel’s backlash, which may be protracted. El Mencho left no clear heir, and the remaining leaders could dispute control. The Jalisco Cartel is also engaged in active turf wars with an array of local groups, especially in Guanajuato and Michoacán. Those smaller outfits could seize this opportunity to try to gain an upper hand. While El Mencho’s death delivered Sheinbaum a win with Washington, it is far from clear the killing will aid the president’s ultimate goal of pacifying Mexico.