Mexico Sent 10,000 Troops to Stop Fentanyl. It Remains Elusive.

The Washington Post

13:24 JST, March 2, 2025

NOGALES, Mexico – When President Donald Trump threatened 25 percent tariffs unless Mexico put a halt to fentanyl trafficking, the government snapped to attention. Mexican President Claudia Sheinbaum dispatched an additional 10,000 national guard members to the border. For more than three weeks, troops have stopped nearly every U.S.-bound car leaving this city, questioning drivers, sliding mirrors under vehicles, poking fiber-optic scopes into gas tanks and walking drug-sniffing dogs around autos.

The result? The troops in Nogales have found 150 fentanyl pills, according to official statistics. Meanwhile, U.S. officials just across the border have seized more than 400,000.

Some critics have dismissed Mexico’s operation as a show, designed to placate an American leader fond of military solutions to complex problems. That misses the point, analysts say. Mexico appears to be making a serious effort to cooperate more on tackling fentanyl and other narcotics. On Thursday, for example, it transferred 29 high-level drug suspects to the United States.

But the border operation underscores the difficulty of finding the opioid – especially for a country with a weak, underfunded security structure.

The fentanyl epidemic is the deadliest in U.S. history. Overdose deaths attributed mostly to the opioid topped 100,000 in 2023, before dropping by more than 20 percent in the 12-month period ending in August, according to preliminary figures. The drug is largely made in small Mexican labs and is highly concentrated, U.S. officials say.

That makes it frustratingly hard to find at crossings like Nogales. About 11,000 vehicles a day crawl north across the border – carrying tourists, shoppers and workers, along with commerce ranging from Ford Broncos to tons of tomatoes. “A pill is very tiny,” said Michael Humphries, the U.S. Customs and Border Protection director of the Nogales, Arizona, border crossing. For smugglers, “concealment locations are pretty unlimited.”

U.S. officials have welcomed the Mexican reinforcements. “We need all the help we can get,” said one veteran antidrug official in Arizona. But the Mexicans’ lack of experience and classified intelligence makes it hard for them to detect fentanyl, said the official, who was not authorized to speak on the record.

“They’re not going to find a lot of these things if they don’t know what they’re looking for,” he said.

– – –

This Arizona crossing shows why it’s hard to stop fentanyl

Arizona has become the principal U.S. entry point for fentanyl, with twice as much seized compared with the California border, according to CBP data. The Sinaloa cartel – believed to be the main Mexican trafficker of fentanyl – “exerts near-total control over the border region south of Arizona,” according to the latest National Drug Threat Assessment by the Drug Enforcement Administration.

Like most countries, Mexico hasn’t traditionally inspected vehicles leaving its territory. That changed in early February. With Trump about to impose 25 percent tariffs, Sheinbaum won a one-month reprieve, by pledging to send 10,000 troops to the border. That roughly doubled the military’s presence there. (Canada, the source of a minuscule amount of U.S.-bound fentanyl and irregular migration, also stepped up enforcement in response to a U.S. tariff threat.)

Mexico’s Operación Frontera Norte – Operation Northern Border – quickly produced some surprises, especially for Americans accustomed to easily crossing the border for holidays or shopping trips.

Jeri Stanfill, a retiree from Arizona, has vacationed in Mexico for 35 years. “I have never been checked by the Mexican nationals, to go back into the US,” she wrote on Facebook.

It makes sense to screen Americans. About 80 percent of people caught bringing fentanyl through U.S. border crossings from 2019 to 2024 were U.S. citizens, according to data compiled by the Washington Office on Latin America, or WOLA. Cartels may have begun recruiting Americans during the coronavirus pandemic, when the border was closed to many noncitizens.

In Nogales, the troops questioned one young American couple last month about where they were coming from, recounted Gen. Anastasio Santos, in charge of the border operation for Sonora state. “Hermosillo,” blurted out the man, just as the woman piped up with a different city: “Puerto Peñasco.” The troops searched the vehicle, finding a plastic bag of fentanyl pills under the spare tire.

Since Operation Northern Border kicked off on Feb. 5, Mexico’s national guard has seized more than 26,000 pounds of drugs, the majority of it methamphetamines. They also detained 819 migrants.

What the troops aren’t finding much of is fentanyl. In total, they have confiscated about 120 pounds of powder and around 51,000 pills. Most of that was found in two vehicles in the tiny town of Oquitoa, 80 miles southwest of the Nogales border crossing.

Does that mean Mexico’s action is meaningless?

No, says David Luckey, a senior researcher at Rand who studies drug policy. Most fentanyl crosses through official entry ports, rather than across the unguarded desert, he noted. Fentanyl is so deadly that authorities need to crack down wherever they find a chokepoint, he said.

“We need to address the entire supply chain,” he said.

Others are doubtful. Adam Isacson, who studies border security for WOLA, said intelligence information is crucial to battling fentanyl traffickers.

“If you don’t know what you’re looking for, who’s who, what money flows look like, what corrupt officials are making your job harder, then just putting a bunch of soldiers there – they’re just scarecrows,” he said.

Santos, the general, acknowledges the deployment hasn’t resulted in a significant increase in fentanyl seizures.

“It isn’t the solution” to the drug problem, he said, as he watched troops search a truck at a checkpoint south of Nogales. “We need more coordinated work between the border authorities of Mexico and the United States – using intelligence – so we can make busts that are more pinpointed, more focused, more targeted.”

– – –

The real problems in seizing fentanyl are structural

Like Santos, Humphries is a drug war veteran, with 38 years of customs enforcement. His CBP agents have seized tens of millions of fentanyl pills in Nogales in recent years. Thanks to huge new X-ray machines, the agents can screen about half the trucks crossing into the United States. But they can only scan around 3 percent of the cars.

“It’s going to take more than law enforcement” to solve the fentanyl problem, he said – with education, counseling and medical services essential. A bipartisan congressional report issued in 2022 came to the same conclusion. It’s so simple to combine chemicals into fentanyl – and it’s so easy to transport – that real progress can come only if Americans curb their appetites for the drug, the report said.

Vanda Felbab-Brown, a security analyst at the Brookings Institution, said Sheinbaum “is clearly trying to respond to Trump’s threats.”

But Mexico’s crime-fighting system is hobbled by corruption and a lack of trained professionals. The country spends relatively little on national defense and domestic security – only about 0.7 percent of its gross domestic product in 2024, said Diego Díaz of the Center for Investigation of Public Policy (IMCO), a Mexican think tank. That figure is expected to drop this year as the government struggles with high debt.

Felbab-Brown said the battle against fentanyl is further complicated by contradictions in Trump’s policies.

“Everyone is chasing undocumented migrants,” she said, including agents from the DEA and Homeland Security Investigations, who have been diverted to that task. “You have a real depletion of capacities on the U.S. side at the same time Mexico is putting in a lot of assets.”

It’s not clear how sustainable the Mexican border operation is. In one city, Reynosa, the national guard had to scale back its vehicle inspections after local officials and business owners complained of traffic backups of up to six hours.

Santos said he had no idea when his national guard reinforcements would leave. Trump has said he will go ahead and impose the tariffs on March 4 if he isn’t satisfied by Mexico’s efforts. “How long we’ll be here will be determined by the U.S.-Mexico agreement,” the general said.