[25] The origins of Los Zetas date back to the late 1990s, when commandos of the Mexican Army deserted their ranks and began working as the enforcement arm of the Gulf Cartel.

[38][39][40] Decena lured more than thirty deserters from the elite Grupo Aeromóvil de Fuerzas Especiales (GAFE) to become his personal bodyguards, and later, as his mercenary wing.

[43] Once Guillén consolidated his power, he expanded the responsibilities of Los Zetas, which began to organize kidnappings,[44] protection rackets,[45] extortion,[46] securing cocaine supply and trafficking routes known as plazas (zones) and executing its foes, often with extreme violence.

[35][52] The Zetas' membership ranges from corrupt federal, state, and local police officers, and former U.S. Army personnel,[53][54][55] to ex-Kaibiles, the special forces of the Guatemalan military.

[4] As other organized crime groups subsequently copied the Zetas' brutal and superfluous methods to ensure they could survive, this resulted in the violence in Mexico escalating to much higher levels and to new forms.

[61] Los Zetas countered by posting their own banners throughout Tamaulipas, noting that they had carried out executions and kidnappings under orders of the Cartel and they were originally created for that sole purpose.

Some sources claim that Guillén, brother of Cárdenas and one of the successors of the Gulf Cartel, was addicted to gambling, sex, and drugs, leading Los Zetas to perceive his leadership as a threat to the organization.

[76] Los Zetas are inherently an unstable organized crime group with a long history of brutal violence, and with the possibility of more if the infighting continues and if they fight on without a central command.

"[98] On 14 July 2013, it was reported that the Mexican Marine Corps captured the Zetas leader Miguel Ángel Treviño Morales, also known as "Z-40" in Anáhuac, Nuevo León, near the border of Tamaulipas state.

[101] His arrest ultimately resulted in the discovery and seizure of a large Zetas weapons cache and supply stash, including "assault rifles, several grenade launchers, magazines, 2,000 rounds of ammunition of various calibres, bullet-proof vests and balaclavas".

[102] On 3 March 2015, Mexican security forces arrested the last known leader of the remaining Zetas structure, Omar Treviño Morales (alias "Z-42") in a suburb in Monterrey, Nuevo León.

[103] On 23 March 2015, Ramiro Pérez Moreno (alias "El Rana"), a potential successor of "Z-42" was captured, along with 4 other men, carrying 6 kilos of cocaine and marijuana, rifles and one hand grenade.

[112] In March 2020, senior Los Zetas operative Hugo Alejandro Salcido Cisneros, also known as "El Porras" or "Comandante Pinpon", was killed in a gun battle with police in Nuevo Laredo.

[115] The massacre of 72 migrants and the discovery of mass graves in San Fernando,[116][117] the assassination of the gubernatorial candidate Rodolfo Torre Cantú,[118] the increasing violence between cartels, and the state's inability to ensure safety have led some analysts to conclude in 2011 that "neither the regional nor federal government have control over the territory of Tamaulipas.

[126] In addition, there are formal charges that three former governors of Tamaulipas – Manuel Cavazos Lerma (1993–1999), Tomás Yarrington (1999–2005), and Eugenio Hernández Flores (2005–2010) – have had close ties with the Gulf-Zeta organization.

[127] On 30 January 2012, the Attorney General of Mexico issued a communiqué ordering the governors and their families to remain in the country as they are being investigated for possible collaboration with cartels.

[132] In mid-2010, both Flores and the mayor of Reynosa, Óscar Luebbert Gutiérrez – both members of the PRI – were criticized for claiming that there were no armed confrontations in Tamaulipas and that the widespread violence was "only a rumor".

[152] As a result, most police forces in Tamaulipas are believed to be susceptible to corruption due to their low wages, and accept bribes from organized crime groups.

[153] The National Public Security System (SNSP) has condemned the low police salaries, and demanded that state and municipal authorities create better payment programs for policemen so they can have a fair wage for themselves and their families.

[156] The following month, the federal government was asked to send in troops to combat the drug cartels in the area, to "consolidate actions on public safety" and "strengthen the capacity of their institutions".

The initial leader of this group was Ashly "La Comandante Bombón" Narro López; she was captured in 2009 in connection to the murder of General Tello Quiñones.

[191] Due to the high level counter insurgency training of the initial members from the Mexican military, Los Zetas have been infamously difficult to disrupt.

[196][197] In 2012, the Obama administration imposed sanctions on Los Zetas as one of four key transnational organized crime groups, along with the Brothers' Circle from Russia, the Yamaguchi-gumi (yakuza) from Japan, and the Camorra from Italy.

[201] In addition, the Obama administration made a very modest effort by way of support for the struggling country although "former drug czar Barry McCaffrey told Congress that Merida, was 'a drop in the bucket'", and that the United States "cannot afford to have a narco-state as [their] neighbour".

[203] The New York Times mentioned that Los Zetas has access to sophisticated tracking software due to the fact that they have infiltrated Mexican law enforcement agencies, and that online anonymity might not be enough protection for Internet users.

[citation needed] According to the U.S. Energy Information Administration, Mexico is responsible for 10% of all of United States petroleum imports and plays an even larger role in exporting to nations in South America.

Los Zetas pose a great humanitarian risk to the regional communities and to those in which its activities extend, including several countries in Central America and across the largest cities in the United States.

Despite this, Los Zetas is characterized as an organized criminal group because it has an expansive membership, has existed over a period of time, and commits serious crimes for the purpose of financial gain.

Los Zetas' original 31 members were soldiers in Mexico's most elite special forces unit, the Grupos Aeromóviles de Fuerzas Especiales (GAFE).

Los Zetas divides its roles and responsibilities along strategic, operational, and tactical lines which allow them to effectively combat rival cartels and engage in illicit activities.