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 Sinaloa Cartel and the Gulf Cartel are two of the dominant drug trafficking groups in Mexico. Rivalry between the groups started in 1999 when the new leader of the Gulf Cartel, Osiel Cardenas, took control of the group and started battling the Sinaloa Cartel for areas of control in the Yucatan peninsula. Tension increased in 2003 when the arrest of Osiel Cardenas altered the previous balance of power between the cartels. The Sinaloa Cartel, with the help of their militia Los Negros, began to challenge the Gulf Cartel's domination of an important drug smuggling route into the United States through the Mexican city of Nueva Laredo. The Gulf Cartel made use of their militia Los Zetas to fight its rivals.
According to Mexican authorities the conflict was mainly over the production and distribution of marijuana, cocaine and synthetic drugs such as methedrine. However, it had also personal aspects: the leader of the Gulf Cartel Cardenas was accused of being responsible for the death of the brother of the head of the Sinaloa Cartel, Guzman, in late 2004. The killing set off a chain of reprisals and led to an escalation of the violence between the two groups in 2005. In 2010, violence between the groups subsided as they allied against an alliance of their enemies made up of the Juarez Cartel, the Tijuana Cartel, the Gulf Cartels former armed wing Los Zetas and the Beltran Leyva Cartel, formerly part of the Sinaloa Cartel.
Both the Gulf Cartel and the Sinaloa Cartel use advanced weaponry such as grenade launchers, as well as guns, to battle each other. Torture, decapitations, and mutilations of the victims' bodies are common. On several occasions threatening messages to the groups' leaders have been found next to the victims' bodies.
The violence has primarily been concentrated in Nuevo Laredo and central Mexico, but in 2008 clashes also took place in Guatemalan border cities and in 2010 there was a clash in Honduras.
The non-state conflict between the Gulf Cartel and the Sinaloa Cartel is first included in UCDP data in 2004. In October of that year, clashes between the two cartels had resulted in more than 25 battle-related deaths.
