The Drug Enforcement Agency describes the Sinaloa Cartel as “one of Mexico’s oldest criminal organizations, and one of the most violent and prolific polydrug-trafficking cartels in the world.” Based in the Mexican state of Sinaloa, the modern iteration of the cartel was founded by Ismael “El Mayo” Zambada and Joaquín “El Chapo” Guzmán Loera, who have been imprisoned in the U.S. since 2016. The power vacuum left by the imprisonment of Guzmán had largely been filled by two competing factions within the cartel: “Los Chapitos,” led by the four sons of Guzmán, and “La Mayiza,” led by Ismael Zambada and his sons. Each faction believes their respective leaders are the true heirs to the Sinaloa Cartel.
Since the arrests of Ismael Zambada and Joaquín Guzmán López, a son of El Chapo, in July 2024, tensions between the two factions have erupted. Zambada alleges that Guzmán López kidnapped and handed him over to law enforcement to secure favorable terms before surrendering to U.S. authorities. The apparent betrayal of Zambada caused a civil war within Sinaloa, with hundreds of cartel members and civilians either killed or missing.
The dramatic rift within the Sinaloa Cartel mirrors that of Los Zetas and the Gulf Cartel in 2010. Formed by Gulf Cartel boss Osiel Cárdenas Guillén in the late 1990s, Los Zetas was the armed wing of the Gulf Cartel composed of Mexican military deserters. Due to the background of its founding members, Los Zetas operated like a paramilitary unit, using advanced weaponry and extreme violence to protect the Gulf Cartel from the Sinaloa Cartel and other rivals. Over time, the role of Los Zetas expanded to include extortion, kidnapping, and more direct involvement in drug trafficking.
Similar to the current civil war in the Sinaloa Cartel, tensions began rising within the Gulf Cartel due to a power vacuum. After Osiel Cárdenas Guillén’s extradition in 2007, three main figures vied for control of the Gulf Cartel: Heriberto Lazcano Lazcano led Los Zetas, while Antonio Cárdenas Guillén and Jorge Eduardo Costilla Sánchez controlled the rest of the organization. Lazcano believed that he and Los Zetas should lead the entire cartel, especially given the expanding responsibilities and influence of his group. Cárdenas Guillén and Costilla Sánchez tried to curb the power of Los Zetas, attempting to reign in their former enforcers. Although the exact catalyst is unknown, tensions erupted in a civil war in 2010 with Los Zetas breaking away from the Gulf Cartel.
The period during and immediately after the split is among the most violent in the history of Mexican cartels. The Gulf Cartel allied with the Sinaloa Cartel, their former rival, while Los Zetas allied with the Sinaloa Cartel’s rivals. The alliances spread the conflict across Mexico, with the national homicide rate increasing by over 28% in 2010. Both factions were significantly destabilized during this period. After a bloody shootout with the Mexican military in 2010, Antonio Cárdenas Guillén was killed, significantly weakening the Gulf Cartel. Los Zetas were also weakened, with Lazcano being killed in 2012 and the Treviño brothers, key members of Los Zetas leadership, being arrested shortly afterwards. Infighting became commonplace within both organizations, with the two organizations further splintering into warring factions.
Today, Los Zetas have been either absorbed into larger cartels or reduced to small, insignificant cells. The Gulf Cartel has been split into four smaller factions, each forming rapidly shifting alliances with each other or other cartels. However, the fragmentation of the two organizations did not stop the violence in Tamaulipas, the state in which they primarily operate. The Department of State classifies Tamaulipas as one of six states in Mexico with a Level 4: Do Not Travel advisory. Notably, other states with a Level 4 advisory are controlled by major cartels, such as the hyper-violent Cártel de Jalisco Nueva Generación (CJNG). Clearly, the fragmentation of Los Zetas and the Gulf Cartel has only led to a prolonged legacy of chaos and extreme violence.
The same story seems to be unfolding with the Sinaloa Cartel’s civil war. Reports of an alliance between Los Chapitos and the CJNG resemble the 2010 alliance between the Gulf and Sinaloa Cartels. Like the Gulf and Sinaloa Cartels prior to 2010, Los Chapitos and the CJNG were originally rivals. The kidnapping of Jesús Alfredo Guzmán, one of El Chapo’s sons, sparked years of violence between the two organizations. Their newfound alliance suggests an intensification of the war between Los Chapitos and La Mayiza and spreads the violence to neighboring states controlled by the CJNG.
La Mayiza has been drawing upon alliances across Mexico as well. The Arzate García brothers control the majority of Tijuana, a Mexican city bordering California and a major drug trafficking center. They are also the godchildren of Ismael Zambada, thus pledging allegiance to the La Mayiza faction. The web of alliances formed by Los Chapitos and La Mayiza is similar to the alliances formed during the war between Los Zetas and the Gulf Cartel. This risks a wave of violence sweeping across the entirety of Mexico rather than localizing the conflict to the state of Sinaloa.
The aftermath of the conflict will likely yield similar results to that of the Zetas-Gulf Cartel split as well. While the Sinaloa Cartel’s factions are controlled by entire families rather than independent criminals like Los Zetas and the Gulf Cartel, there is a high chance of fragmentation into smaller divisions after the civil war. It is unclear whether La Mayiza will remain loyal to Ismael Zambada and his sons after the elder Zambada’s arrest. Similarly,two of El Chapo’s sons have already been arrested, leaving a power vacuum and uncertainty over the group’s long term leadership. If the conflict within the Sinaloa Cartel continues to follow in the footsteps of Los Zetas and the Gulf Cartel, it is likely that violence will continue long after the civil war ends.
Preventing this dangerous outcome will be difficult. As seen by the Mexican government’s intervention in the Gulf Cartel and Los Zetas after 2010, deposing cartel leaders will only lead to greater chaos and fragmentation. However, Sinaloa’s civil war also presents a unique opportunity for authorities to target the weakened cartel. A careful, measured approach to permanently dismantling the cartel is urgently needed to stop further bloodshed in Mexico.