MEXICO CITY — A former Mexican defense minister was arrested on Thursday night after arriving at Los Angeles International Airport with his family, according to the Mexican government, becoming the first high-ranking military official to be taken into custody in the United States in connection with drug-related corruption in his country.
The former official, Gen. Salvador Cienfuegos Zepeda, who was Mexico’s defense minister from 2012 to 2018, was arrested by American officials at the request of the Drug Enforcement Administration and will face drug and money-laundering charges in the United States, according to a federal law enforcement official in New York.
The news not only casts a pall over Mexico’s fight against organized crime, but also underscores the forces of corruption that touch the highest levels of the government. General Cienfuegos was defense minister throughout the administration of President Enrique Peña Nieto, who left office two years ago.
General Cienfuegos’s arrest comes 10 months after the retired police official who once led the Mexican equivalent of the F.B.I. was indicted in New York on charges of taking bribes while in office to protect the Sinaloa drug cartel, one of Mexico’s most powerful criminal mafias.
The official, Genaro García Luna, served as the head of Mexico’s Federal Investigation Agency from 2001 to 2005, and for the next six years was Mexico’s secretary of public security, a cabinet-level position. In that role, he has the task of helping the president at the time, Felipe Calderón, create his strategy to battle their country’s drug cartels.
Both Mr. García Luna and General Cienfuegos served at the highest reaches of the Mexican government at a time when homicides spiked to historic levels, drug cartels waged war, and under Mr. Peña Nieto, military operations were expanded.
“There has never been a minister of defense in Mexico arrested,” said Jorge Castañeda, a former Mexican foreign minister. “The minister of defense in Mexico is a guy that not only runs the army and is a military man, but he reports directly to the president. There is no one above him except the president.”
Mexico’s foreign minister, Marcelo Ebrard, confirmed the arrest in a Twitter post. He said he had been told only on Thursday night by the United States ambassador to Mexico, Christopher Landau, that General Cienfuegos had been taken into custody.
The exact charges that General Cienfuegos will face were not immediately clear, and Drug Enforcement Administration officials did not respond to requests for comment.
“This is a huge deal,” said Alejandro Madrazo, a professor at CIDE, a university in Mexico City. “The military has become way more corrupt and way more abusive since the war on drugs was declared, and for the first time they may not be untouchable — but not by the Mexican government, by the American government.”
Mexico’s military has played a central role in public security since the crackdown on the drug cartels began in 2006, deploying soldiers to regions overrun by organized crime. The secretary of defense oversees that effort.
Suspicions of corruption in the Mexican military have long surfaced in private conversations, but the military has an extraordinary amount of autonomy, seldom bowing to political pressures and typically enjoying protection by the president, who relies on it for the nation’s domestic defense.
With the military front and center in the fight against narcotics trafficking, the Mexican government has never built an effective police force. The use of soldiers who are trained in combat but not policing has brought problems of its own.
In December 2017, Mexico passed a security law cementing the military’s role in fighting the drug war, outraging the United Nations and local and international human rights groups. They warned that the measure would lead to abuses, leave troops on the streets indefinitely and militarize police activities for the foreseeable future.
General Cienfuegos repeatedly defended the military, saying it was the only institution effectively confronting organized crime. As drug violence rocketed in recent years, he asked again and again that the federal government provide a legal framework that protects the forces, saying the need for it was greater than ever.
“Today the crimes we are dealing with are of another level and importance; they involve a lot of people, sometimes entire families, and we are acting without a legal frame,” General Cienfuegos said in March 2018. “Without it, our help is impeded.”
Still, the military has repeatedly been singled out for human rights abuses and the use of excessive force, including accusations of extrajudicial killings that dogged the armed forces throughout General Cienfuegos’s tenure as defense minister.
But no high-ranking Mexican military official has been charged with money laundering and drug trafficking. Such charges would represent a new front in the effort to combat the corruption and extraordinary power wielded by organized crime in Mexico.
General Cienfuegos’s arrest does not appear to have been a joint operation with the Mexican government. The case against Mr. García Luna, the retired police official, was the direct result of testimony in the New York trial of the drug lord Joaquín Guzmán Loera, better known as El Chapo, who ran the Sinaloa cartel. It was unclear on Friday morning whether the arrest of General Cienfuegos was also related to the case against Mr. Guzmán, who was convicted in February 2019 after a three-month trial in Federal District Court in Brooklyn.
The Guzmán trial exposed the inner workings of his sprawling cartel, which over decades shipped tons of drugs into the United States and plagued Mexico with relentless bloodshed and corruption.
In 2016 and 2017, the years when Mr. Guzmán was arrested for a final time and sent to New York to be prosecuted — at a time when General Cienfuegos was defense minister — Mexican heroin production increased by 37 percent, and fentanyl seizures at the southwest border more than doubled, according to the Drug Enforcement Administration.
The D.E.A. noted as the case against Mr. Guzmán unfolded that the Sinaloa and Jalisco New Generation cartels “remain the greatest criminal drug threat” to the United States.
Prosecution of the Guzmán case was years in the making, and his trial drew upon investigative work by the F.B.I., the D.E.A., the United States Coast Guard, Homeland Security Investigations and federal prosecutors in Chicago, Miami, San Diego, Washington, New York and El Paso, Texas. The trial team also relied on scores of local American police officers and the authorities in Ecuador, Colombia and the Dominican Republic.
Witnesses testified that bribes had been paid to Mr. García Luna and a host of Mexican generals and police officials, and almost the entire congress of Colombia.
“One of the important things about this conviction is that it sends a resounding message,” Ángel Meléndez, special agent in charge for Homeland Security Investigations, said at the time. “You’re not unreachable, you’re not untouchable, and your day will come.”
Reporting was contributed by Natalie Kitroeff from Mexico City, Zolan Kanno-Youngs from Washington, Alan Feuer from New York and Mike Ives from Hong Kong.