In this Saturday, Feb. 22, 2014, photo, Joaquin 'El Chapo' Guzman is escorted to a helicopter in handcuffs by Mexican navy marines at a navy hanger in Mexico City, Mexico. Guzman, the head of Mexico's Sinaloa Cartel, was captured overnight in the beach resort town of Mazatlan. (Eduardo Verdugo/The Associated Press)
WASHINGTON — The United States is quietly expanding its training of Mexico's armed forces, helping to reverse decades of mistrust that made Mexico's military reluctant to cooperate with its northern neighbor.
The amount the Pentagon spent on training Mexico's armed forces, though small, increased to more than $15 million last year, up from about $3 million in 2009, according to U.S. Northern Command, which oversees U.S. military contacts with Mexico.
The training comes as Mexico's armed forces have been drawn deeper into the country's war on drugs and organized crime.
"For decades, Mexico's military tried to remain autonomous from the U.S. military," said David Shirk, a fellow at the Wilson Center.
U.S. military officials are reluctant to discuss the relationship openly because of sensitivities in Mexico about appearing dependent on American help. In a statement, the Pentagon said the U.S. military participated in 150 "engagements" with Mexican troops on both sides of the border, "sharing training opportunities with more than 3,000 Mexican soldiers, sailors, airmen and Marines."
The statement said the Pentagon's "interactions" with Mexico's military have expanded over the past three years. Mexican government officials declined to speak on the record about the training.
The Mexican navy and marine corps have been particularly receptive, allowing the United States to expand its training with Mexico's armed forces and build trust.
"Our security agencies have focused heavily on cooperation with the navy and marines," said George Grayson, a professor at William and Mary who has written a book about Mexican drug cartels.
By contrast, the army is a more "insular" institution less willing to cooperate with foreign military forces, Shirk said.
"The navy has earned a tremendous amount of trust from American authorities," Shirk said.
The army is more susceptible to corruption, since its soldiers have been deployed throughout the country in fixed locations, where there are more opportunities to be bribed. They have direct contact with drugs through eradication efforts.
The Mexican marines are used only for targeted raids and are more insulated from bribes or intimidation, Shirk said.
Grayson said the navy and marines were used for one of the first times when they launched a raid in 2009 that killed Arturo Beltrán Leyva, the leader of a major cartel in Cuernevaca.
The forces used in the raid received extensive training from the United States, according to a classified U.S. Embassy message that was released by WikiLeaks.
The U.S. government initially provided intelligence to the army on the whereabouts of Beltrán Leyva but was reluctant to act, the message said.
"Its success puts the Army in the difficult position of explaining why it has been reluctant to act on good intelligence and conduct operations against high-level targets," the embassy cable said, according to WikiLeaks.
The success of that raid led to a heavier reliance on the Mexican navy and marines. Of 22 raids on top-level traffickers from 2006 through 2012, seven were conducted by the navy and marines, according to Grayson.
The army was responsible for eight raids during that time, even though it is a much larger force. The federal police conducted eight raids.
Grayson said Mexico's navy is more willing to use modern intelligence methods, such as surveillance drones, to target kingpins. It is learning many of the techniques from Americans.
The U.S. military has provided a range of training for Mexican forces, ranging from small-unit tactics to helicopter maintenance.
The military training is part of a larger program to support Mexico's war on drugs. The cornerstone of that is the Merida initiative, a $2.1 billion program started in 2007. The program has provided equipment and training for Mexico's judiciary and law enforcement agencies.
That program has opened the door to military contacts, Shirk said. "That really was a watershed moment," he said.