The Obama administration's chief law enforcement officials traveled to Cuernavaca April 2 on Thursday to meet with their Mexican counterparts and begin formalizing plans to join forces against the drug cartels. "There's no doubt that the vast majority of weapons seized in Mexico come from the United States," said Attorney General Eric H. Holder Jr. "This is a reality we have to face in the United States, and it's one Mexicans have long had to confront. We will take responsibility on our side to work with Mexico to get a handle on this serious problem."

The meeting, which was also attended by Homeland Security Secretary Janet Napolitano, was held as Mexican authorities announced the arrest of a top leader of the Juárez Cartel as he was jogging in a park near his home in Mexico City's upscale Bosques de las Lomas district. The suspect, Vicente Carrillo Leyva AKA "El Ingeniero" (The Engineer), 32, is the son of the cartel's founder, Amado Carrillo Fuentes AKA "El Señor de los Cielos" (Lord of the Skies)—who died while undergoing plastic surgery 13 years ago.

The authorities said Carrillo Leyva, a fugitive from justice for 12 years, controlled many of the cartel's operations, including transporting heroin, laundering drug profits and acquiring weapons. He will be held in arraigo—pending charges—as the Investigative Sub-prosecutor for Organized Crime (SIEDO) examines his case. His younger brother, Rodolfo Carrillo Leyva AKA "El Niño de Oro" (Golden Boy), was assassinated in 2004. His arrest was the second in two weeks that authorities claimed as a blow against the new generation of cartel bosses that the Mexican media have dubbed "narco-juniors." On March 19, Mexican federal police arrested Vicente Zambada Niebla, also in his 30s, described as a leader of the Sinaloa Cartel. (El Universal, April 4; NYT, April 3; La Jornada, April 2)

In what was hailed as another sign of the new era of cooperation between Washington and Mexico City, a leading member of the Gulf Cartel who was extradited last year pleaded guilty in federal court in Houston March 31 to threatening two US agents at gunpoint. Juan Carlos de La Cruz Reyna admitted that he was among the gunmen who accosted the two agents, Joe Dubois of the DEA and Daniel Fuentes of the FBI, in 1999 as they drove to meet an informant in Matamoros. The cartel's boss, Osiel Cardenas Guillen, was also present, the authorities said. He is also awaiting trial in Houston. (NYT, April 1)

President Felipe Calderón, during an official visit to London this week, said his government and the US would work as partners in the fight against the cartels but would not conduct joint military operations. Sharing of intelligence will continue, he told reporters, but US forces will not be conducting raids on Mexican soil. (NYT, March 31)

See our last post on Mexico's narco wars.

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