With continual flux of alliances and rivalries, figuring out the power structures of the Mexican cartels can get just a bit confusing. We're taking a look at the Mexico cartels, faction by faction, to see just what is happening right underneath our nation's nose.

First up, the most dangerous and deadly of them all: Los Zetas.

Drug Cartel:  Los Zetas

Location:  International, with a presence in Tamaulipas, Nuevo Leon, Coahuila, Veracruz, Tabasco, Campeche, Yucatán, Quintana Roo, San Luis Potosí, Chiapas, Puebla, Tlaxcala, Hidalgo, Querétaro, Chihuahua, Guerrero, Oaxaca, Guanajuato, Aguascalientes, the United States, Guatemala, and Italy.

Zetas control at least 11 states, making them the cartel with the largest territory control. They are headquartered in Nuevo Laredo, Tamaulipas, which is also home to the Gulf Cartel.

Los Zetas are primarily based in the border region of Nuevo Laredo and Coahuila, but there are hundreds more offshoots located throughout the country.

Zetas also operate throughout the Gulf of Mexico, in the southern states of Tabasco, Yucatán, Quintana Roo, and Chiapas, and in the Pacific Coast states of Guerrero, Oaxaca, and Michoacán, as well as in Mexico City.

They are also active in several states in the United States, especially in Texas.

Los Zetas cartel also has important areas of operation in Guatemala and in Italy, with the 'Ndrangheta.

Current Leaders: Omar Trevino Morales, or "Z 42"

History: Los Zetas came together in the late '90s as a mercenary faction of the Gulf cartel, before splitting off a decade later to form their own narco-trafficking cartel.

When Osiel Cárdenas Guillén took control of the Gulf Cartel in '99, he found himself in the midst violent turf war. Cárdenas sought out Ruben Salinas, or "el Chato," a retired Army lieutenant to help.

El Chato lured about 30 army deserters to become Cardenas Guillen's bodyguards, enticing them with high salaries -- at least compared to the Mexican Army -- and increased power, in return for protecting Cardenas Guillen from rival drug cartels and from the Mexican military.

Los Zetas quickly gained responsibility in the Gulf cartel, organizing kidnappings, protection rackets, extortion, executions, and securing drug trafficking routes.

After Cardenas Guillen's extradition in 2007, Los Zetas took a more active leadership role within the Gulf cartel. After the capture and extradition of Cárdenas, Los Zetas had become so powerful that they outnumbered Gulf Cartel in revenue, membership, and influence.

The Zetas broke apart from the Gulf cartel in 2010, and have quickly become the most dangerous and deadly cartel in Mexico. Zeta operatives now include corrupt former federal, state, and local police officers, and ex-Kaibiles, which is the Special Forces of the Guatemalan military.

Power Structure:  Los Zetas is considered by the U.S. government to be the "most technologically advanced, sophisticated, and dangerous cartel operating in Mexico." Unlike most of the other cartels in Mexico, only about half of the Zetas efforts are focused around drug trafficking.

With the help of the ex-military and police presence in the cartel, Los Zetas have set up camps to train recruits as well as corrupt ex-federal, state, and local police officers; these camps have been identified as having a similar setup as military GAFE training facilities.

Testimony from the former Defense Secretary Clemente Vega in '05 indicated that Los Zetas had hired at least 30 former Kaibiles from Guatemala to train new recruits because the number of former Mexican special forces men in their ranks had shrunk.

Alliances:
Beltrán-Leyva Cartel
Juárez Cartel
'Ndrangheta
Los Mazatlecos

Rivalries:
Gulf Cartel
Sinaloa Cartel
Knights Templar Cartel
Jalisco New Generation Cartel

In-fighting has been an issue for Los Zetas; they are an unstable organized crime group with a long history of brutal violence.

Crimes:
 Cancun Cave Killing -- Not far from the tourist beaches of Cancun, police in June 2010 found six bodies which were presumed to have been killed by the Zetas. Three had their hearts cut out; three had the letter Z carved into their abdomens.

Migrant Killings -- In 2010, Zetas came across a group of Central American immigrants making their way through Mexico on the way to the U.S., and they held the group for ransom. They ultimately killed all 72 for not paying the ransom and refusing to work for the cartel.

Murders of Two American Officials -- Two American immigration officials, Jaime Zapata and Victor Avila, were driving along a main road from Mexico City to Monterrey in February 2011, when they were attacked and killed by the Zetas at a roadblock.

City Hall's Hanging Bodies -- At least 23 bodies were found hanging in Nuevo Laredo around City Hall in 2012.

And they've been pinpointed for a ton more: The 2008 Morelia grenade attacks; 2010 San Fernando massacre; 2011 San Fernando massacre; the massacre of 27 farmers in Guatemala; 2011 Monterrey casino attack; the Altamira prison brawl and Apodaca prison riot, just to name a few.