Latest Mexico drug arrest may cripple Gulf cartel MEXICO CITY - Authorities have captured the top leader of the Gulf cartel, a potentially fatal blow to one of Mexico's major drug-trafficking networks that could also unleash a violent power struggle that would pose an immediate and explosive challenge to the incoming government of President-elect Enrique Peña Nieto. It is the second big catch of a suspected Gulf cartel capo in 10 days and essentially wipes out the leadership of an organization that once dominated large parts of Mexico. The cartel still controls important smuggling routes to the United States through the northeastern border region. Jorge Eduardo Costilla Sanchez, alias "El Coss," was arrested Wednesday night at a home in the eastern port city of Tampico, in the border state of Tamaulipas, navy spokesman Vice Adm. Jose Luis Vergara said Thursday. He said Costilla did not resist, but five of his bodyguards were captured in an earlier shootout; other gunmen fleeing that skirmish apparently led troops to Costilla's hide-out. Flanked by masked marines, Costilla was presented to reporters in Mexico City on Thursday morning. Mustachioed and beefy, he remained stone-faced during the appearance. He stood before a table laden with guns, several hundred rounds of ammunition and a collection of high-priced jewelry, all seized in the raid that ended in his capture, Vergara said. Costilla was one of the most-wanted fugitives in Mexico, whose government had offered a reward of about $2.3 million. In the United States, where he is also wanted on drug-trafficking charges and for allegedly attempting to kill U.S. federal agents, officials had placed a $5-million bounty on his head. The Gulf cartel had been losing ground to its onetime ally and armed wing, the vicious Zetas paramilitary force, and, to fight back, formed a partnership with the powerful Sinaloa cartel, Mexico's largest. Together, they waged brutal warfare with the Zetas over control of an ever-widening swath of Mexico, from Tamaulipas down the eastern coast through Veracruz state and westward into the once-tranquil, prosperous state of Nuevo Leon. The region saw some of the most ghastly bloodshed of the drug war, including beheadings, massacres of migrants and the dumping of large numbers of bodies in main thoroughfares. The demise of the Gulf cartel's leadership foretells another likely battle that will be very bloody as gangs scramble to fill the void and seize Gulf assets. Second-tier Gulf lieutenants may vie violently for control, while the Zetas could also sense an opportunity to step up efforts to destroy what's left of the Gulf cartel. And the Sinaloa cartel, fighting for routes and market share in the northeast through its Gulf proxy, will probably have to enter the fray more directly. That will hand an ever-more messy landscape to Peña Nieto, who takes office Dec. 1 and will be under pressure to act quickly to quell violence and prove his own mettle in handling drug cartels. "This could mean a very rough ride for Peña Nieto in the first few months," Alejandro Hope, an analyst and former Mexican intelligence official, told The Times. "He will need to quickly send a message that he is tough, that he is not a pushover" in the drug war. He will have to out-Calderon Calderon. President Felipe Calderon and his government celebrated the capture of Costilla, part of their controversial strategy of going after the senior leaders of drug-trafficking organizations in the hope of fracturing and weakening their operations. More than 55,000 people have been killed since Calderon launched his military-led offensive against the cartels shortly after he took office in December 2006. The captures of Costilla, 41, on Wednesday and of Mario Cardenas Guillen last week in effect wipe out the traditional leadership of the Gulf cartel, one of the oldest in Mexico. Cardenas is the brother of Osiel Cardenas Guillen, a longtime boss of the organization who was arrested in 2003 and extradited to the United States in 2007. He entered a plea agreement in a Texas court in early 2010, receiving 25 years amid suspicion that he was cooperating with U.S. authorities. It may be that cooperation that has helped U.S. and Mexican authorities penetrate the Gulf cartel more successfully than most other drug gangs. And Vergara, the navy spokesman, suggested that Costilla's detention was a direct result of information provided by Mario Cardenas Guillen. In November 2010, another of the Cardenas Guillen brothers, Antonio Ezequiel (alias Tony Tormenta), who had assumed the leadership after Osiel's removal, was killed in a gunfight with Mexican marines, the military branch credited with some of the most important scores in the drug war. "This capture ... puts an end to a generation," Ricardo Ravelo, an expert on cartels who has written extensively on the subject, said in a radio interview. It also leaves the Zetas solidly as the second-most important cartel in Mexico, after Sinaloa, he said. Yet it is not altogether clear that the Zetas are in a position to take full advantage of the Gulf cartel's weakness. The Zetas are reported to be in the throes of infighting and divisions - possibly a product of how rapidly they expanded in recent years - that could hamper their ability to exploit the moment. Eduardo Guerrero, a Mexican scholar who specializes in security issues, said both the divisions in the Zetas and the debilitation of the Gulf cartel could end up limiting any violence as a result of Costilla's arrest. "The detention could provoke a fragmentation of the cartel," he said via email. It is probable that the Sinaloa cartel would absorb some [Gulf] cells, while others could also affiliate with the Zetas. Other experts criticized the Calderon strategy of going after cartel leaders without pursuing their money or otherwise truly hurting their operations. Peña Nieto has been vague about his security plans except to vow to continue the war on drug gangs while focusing energies on the crimes of homicide, extortion and kidnapping. "The problem is that killing or capturing the capo does not end the business," said Jose Reveles, author of "El Cartel Incomodo" (The Uncomfortable Cartel), about the Sinaloa network. The violence continues. The trafficking continues. The fortunes remain intact.