By Tim Lister, Ruben Correa, CNN
(CNN) — The killing of Jalisco cartel boss Nemesio Oseguera, aka “El Mencho,” could fuel a turf war among drug-trafficking gangs in Mexico, analysts say, with the rival Sinaloa cartel already riven by infighting.
The Jalisco and Sinaloa cartels have long fought to dominate the lucrative US market for illegal drugs, including cocaine, heroin and fentanyl trafficking, and they increasingly compete for control of illegal migration into the US.
The US government has described the Jalisco New Generation Cartel (known by the Spanish-language abbreviation CJNG) as “one of the five most dangerous criminal organizations in the world,” with operations earning billions of dollars in revenue.
The US State Department designated the CJNG as a foreign terrorist organization in February 2025.
Who takes control of the group, or whether it splinters into factional bloodletting, will have a huge impact on drug trafficking in the Americas.
Oseguera, founder of the CJNG, had taken advantage of Sinaloa’s disarray, rapidly expanding the reach and activities of the group to include fuel theft, human trafficking and financial fraud. The Jalisco group even formed an alliance with part of the Sinaloa cartel to deepen its divisions.
Former Sinaloa leaders Joaquin “El Chapo” Guzman and Ismael “El Mayo” Zambada are now held in the United States. Guzman was extradited in 2017 and Zambada last year, spurring a battle for control of the group between Guzman’s sons and a faction loyal to Zambada.
The history of trafficking groups, in both Colombia and Mexico, is one of constant upheaval, driven by territorial rivalry and greed. Rivals pounce on any sign of weakness or division.
The Sinaloa conflict was fueled by the lack of a clear family successor, and the same may now apply to CJNG. El Mencho’s son Rubén Oseguera is currently serving a sentence in the United States, having been extradited in 2020. His wife was arrested in Mexico on money-laundering charges in November 2021. Two brothers are also in Mexican jails.
“The Jalisco cartel’s line of succession has been broken,” according to Mexico City-based security expert David Saucedo. Only one brother remains, along with a stepson who, according to Saucedo, “still lacks influence among other cartel commanders.”
Four CJNG commanders may be vying for supremacy and “may enter a succession war to define control of the cartel, though a negotiated transition is also possible,” Saucedo said.
Oseguera was unchallenged as the leader of the CJNG, but rumors that he was sick had already sparked defections. The Mezcales, a splinter faction of the CJNG in the state of Colima, declared four years ago that it was ending its affiliation with CJNG in the belief he had died. The defection led to weeks of gang-related violence.
The CJNG-Sinaloa contest spans several Mexican states as the two groups “dispute territorial control for various drug trafficking routes in central and northern Mexico,” according to InSightCrime, which tracks the cartels. One area of intense competition is Mexicali, capital of the Mexican state of Baja California, which borders the US. Roadblocks