SUMMARY

The outbreak of fighting between different drug-trafficking gangs in Mexico can be understood against the background of changes in the Mexican political landscape during the last decades. During the 1980s, there was a loose network of drug smugglers controlling their own "plaza" for drug trafficking. Governmental authority was highly centralized under PRI (Partido Revolucionario Institucional, Institutional Revolutionary Party) rule and by bribing high officials, the drug smugglers could control their businesses without getting interrupted by the authorities. When single-party rule started to give way to local opposition these networks and relationships were transformed, to the advantage of some actors but to the disadvantage of others. The drug cartels started to fight each other for control over territory and previous alliances fell apart.

The Beltrán Leyva Cartel originates from the Sinaloa Cartel but in 2008 the Beltrán Leyva brothers broke with Guzman, the leader of the Sinaloa Cartel, as a result of Guzman's suspected involvement in the capture of Alfredo Beltrán Leyva in January 2008. This set of a series of clashes between the two cartels during the spring of 2008 including heavy fighting after the killing of Guzman's son in Culiacan, Sinaloa on 8 May. The Beltrán Leyva Cartel and the Sinaloa Cartel have since then clashed sporadically over different drug smuggling routes and “plazas” mainly in the western Sinaloa state but occasionally also in the Baja California Sur and Durango states.

The non-state conflict between the Beltrán Leyva Cartel and the Sinaloa Cartel was first included in UCDP data in 2008. In April that year, clashes had resulted in more than 25 battle-related deaths.