The U.S. military is getting ready to send its elite troops to help in the fight against Mexico's drug lords. American special operations forces will expand their training of Mexican commando teams, teaching them to hunt cartel chieftains like they were al-Qaida extremists. It's a sign the U.S. is preparing for a long shadow war against the cartels.

The training, detailed in documents obtained by the Associated Press, will be reportedly conducted under an expanded special operations program based at the U.S. Army Northern Command's headquarters – which oversees the Pentagon's military operations on the continent. The program has previously tutored "Mexican military, intelligence, and law enforcement officials to study U.S. counterterrorist operations," according to the AP. But in a memo reportedly obtained by the news agency, outgoing Defense Secretary Leon Panetta authorized an expansion of the program that could "eventually triple from 30 [people] to 150," placing a general instead of a lieutenant colonel in charge, and creating a new headquarters.

That doesn't mean the U.S troops will be hunting the cartels themselves. American officials reportedly deny that special forces will be operating within Mexico, due to Mexican laws preventing foreign agents from operating on national soil with weapons. But the U.S. government has other means to attack the cartels – including the power of the purse.

The Treasury Department on Thursday slapped sanctions on an obscure but deadly drug cartel that's been gaining strength of late. The Treasury Department calls them the Meza Flores Drug Trafficking Organization, named after its leader, Isidro Meza Flores or "Chapito Isidro." And on Thursday, the department announced it has added the group to its list of designated foreign narcotics traffickers. Under a U.S. law called the Kingpin Act, that freezes the group's assets within U.S. borders and allows the government to slap hefty penalties on U.S. citizens caught doing business with them.

But in Mexico, the group has gone by other names, such Los Mazatlecos and La Oficina, or "The Office." They are "one of the primary rivals to the Sinaloa Cartel in the Mexican state of Sinaloa," the Treasury Department noted in a statement. Because of this, the cartel has fought an "extremely violent turf war ... which has resulted in the quadrupling of drug-war killings in the last four years and an increase in kidnappings and arson within the state of Sinaloa."

The cartel is also responsible for smuggling vast amounts of cocaine, marijuana, heroin and methamphetamine into the United States, according to the Treasury Department. In addition to sanctioning the cartel, the U.S. has also moved to add Chapito Isidro's family to its list, including his wife, parents, sister and uncles. Also on the list are several companies allegedly owned by the family, including a gas station, a "grain transportation company," and a construction company.

The Meza Flores Cartel. Illustration: Treasury Department The Meza Flores Cartel. Illustration: Treasury Department

But Chapito Isidro and his gang have also been a thorn in the side of the Sinaloa Cartel for several years. His group first came to public attention after kidnapping and killing two people "as a threat to their criminal rivals," according to Tijuana news magazine Zeta. He's "considered a young man, shrewd and very bloody," noted the magazine. He's been allegedly involved in the drug trade since the 1990s, and the U.S. believes he's operated out of the town of Guasave, Sinaloa, since 2000. He also reportedly controls territory throughout northern Sinaloa and the Baja California resort towns of Los Cabos and La Paz, and has been bolstered by an alliance with drug lord Hector Beltran Leyva, the surviving leader of the fading Beltran Leyva Cartel.

It's also a wonder how he's survived deep in Sinaloa's home territory. One theory has it that Chapito Isidro has used Sinaloa's mountains north of Guasave – near the town of Choix – to outmaneuver both the Sinaloa Cartel and the military, mounting ambushes in narrow passes with the help of gunmen and vehicles sent by allies among the Zetas.

The cartel has also been referred to as an amalgam of gangsters from different groups all out to destroy the Sinaloa Cartel. But the Mexican attorney general's office has since considers the group to be "a new criminal organization reaching the rank of cartel" with the "structure, violence and danger," according to Zeta. That's not good news, because it wasn't like we were running low on drug cartels. But there's seemingly no shortage of U.S. and Mexican commandos either.