The cartel's paramilitary branch, the Zetas, consisting of deserted Mexican and Guatemalan Special Forces, are particularly fearsome, applying heavy weapons, most of them imported from the United States, and operate with military precision. The Zetas are blamed for the terrorist attack on Mexico's independence day celebration in Morelia on September 16, 2008.
The cartel was founded in the 1970's by a group of alcohol smugglers. The Gulf Cartel was led by Osiel Cárdenas who was arrested in 2003 and extradited to the United States in 2007. Since then the Zetas have risen in the power structure, with Zeta commander Heriberto Lazcano Lazcano often being considered the new leader of the Cartel.
The Gulf Cartel's main rival is the Sinaloa Cartel from Joaquin "El Chapo" Guzmán, while it is allied with the Tijuana Cartel. The Gulf Cartel is reported to have presence in Mexico, the United States, Guatemala and Italy amongst other countries. Considering that Mexican drug cartels get over 90% of their weapons in the United States, the Mexican government has repeatedly blamed the cartel's strength on the absence of any serious gun control policies in the United States.