Mexican Marines arrested alleged Gulf Cartel leader Jorge "El Coss" Eduardo Costilla Sanchez on Thursday. On Tuesday, they arrested another important member, Mario Cardenas Guillen who is the brother of the former leader of the Gulf Cartel. While the arrests of two high-level Gulf Cartel members might appear to be a crippling blow to the organization, it instead could end up causing more violence and might not have much effect at all on drug trafficking. The US is fighting a hydra-headed drug cartel nemesis on the US-Mexico border. Chop off one head and another appears. Decimate one cartel by arrests and it splits into parts or regroups and then continues business as usual.

What happens across the border in Mexico is not isolated to that country. The corruption and money laundering has a global scope, including in our own country.  Sylvia Longmire, author of "Cartel: The Coming Invasion of Mexico's Drug Wars" says drug cartels are already well-established in US. In an IVN interview, she said "as cartels get squeezed tighter by US and Mexican authorities, they’ll get more desperate to maintain their profits and move drugs across the border; this means they’ll be more likely to engage in risky behavior, i.e. engaging US law enforcement."

The arrest of El Coss will certainly impact the Gulf Cartel. A comment on Borderland Beat, an indispensable source of drug war news, explains what could happen next and how victory over the Gulf Cartel is an illusion.

The Gulf Cartel is done. The government has cut off all the heads of that cartel. Seems like a victory but the capture will create a split like what happen to La Familia Michoacana when Chayo got killed. After that, Los Caballeros Templarios was created and more violence was the result of that split. All in all, the arrest is good news for Los Zetas. Which for the majority of people it will be bad news since Los Zetas will move into the territory controlled by the now basically dismantled Gulf Cartel.

However, Nathan Jones, Postdoctoral Fellow in Drug Policy at the Baker Institute, says the Gulf Cartel will probably survive by continuing their alliance with the Sinaloa Cartel, a view somewhat shared by Longmire.

However, this situation also presents a huge opportunity to the Sinaloa Federation. Joaquin "El Chapo" Guzmán has been fighting Los Zetas on many fronts for years. He may be able to prop up what's left of the CDG [Gulf Cartel] in Tamaulipas and take the fight to Los Zetas instead.

The two primary cartels in Mexico are the Sinaloa Cartel and Los Zetas. They are deadly enemies. The Gulf Cartel controls a strategic part of northeast Mexico sought by both cartels. The Gulf Cartel had already joined with Sinaloa in opposition to Los Zetas. Rival factions now split the Zetas and Gulf Cartel. In addition, the Zetas originally were the enforcer arm for the Gulf Cartel before breaking off on their own.

Relations between and within drug cartels change rapidly, which makes determining what they are doing more difficult. This in turn makes things more perilous for the United States in its attempts to stop drug cartels. We know only opaquely who the cartel leaders are, where they are, and what we are dealing with.