Not a great deal has been written or said in the U.S. media about the Cartel de Jalisco Nueva Generacion. However, especially in light of events over the past month, the cartel has begun to emerge as the foremost paramilitary force in Mexico.

The cartel itself appears to have arisen from the disintegration of the Sinaloan capo Ignacio Coronel’s network in southern Mexico that included the Milenio Cartel, headed by Oscar Orlando Nava Valencia. After Coronel was killed and Valencia captured, the CJNG emerged as the successor to the Sinaloa-run network, following the shaking out of at least two different factions—La Resistencia and Los Torcidos. Los Torcidos came out on top, and became the Cartel de Jalisco Nueva Generacion under the apparent leadership of Nemesio Oseguera Ramos, alias ‘El Mencho.’

The group has been extraordinarily violent even by the standards of the Mexican narco-insurgency. Homicides have risen following their rise, and they have embarked on a systematic offensive against Los Zetas. There is some disagreement as to whether the term “Mata-Zetas,” or Zeta-Killers, refers to the entire cartel, or a direct-action sub-cell of the organization, but it is a term that has been widely used in reference to the CJNG.

Los Zetas hasn’t been the only rival cartel targeted by CJNG. The Cabelleros Templarios have also felt the pressure, as the CJNG has extended its influence into Michoacan. There have been conflicting stories coming out of southern Mexico about the autodefensas, the self-defense militias formed over the past couple of years to fight the Templars (which organization, ironically, got started as just such a self-defense militia to fight Los Zetas).