Mexico deploys 10,000 troops to the US border

On the Mexican side of the border that runs between Nogales, Sonora and Nogales, Arizona, a dozen soldiers stand guard. They flag down some of the northbound cars for checks, waving others through. Nogales is the busiest crossing-point between Sonora and Arizona. People made some 10.6m crossings into the United States using it in 2024. It is also the primary route by which fentanyl is smuggled in. Of the ten tonnes of the stuff seized by US Customs and Border Protection (CPB) in 2024, some 60% was found at Nogales and other smaller Arizona-Sonora crossings. Luis Arturo Corrales Ley, the public-safety commissioner in Nogales, Sonora, calls his state a “springboard for drugs”.

Mexico’s president, Claudia Sheinbaum, hopes to break that springboard by seizing much more fentanyl on her side of the border, thereby reducing the amount that the CBP finds and appeasing America’s president, Donald Trump. On February 4th she promised to send 10,000 additional members of Mexico’s National Guard to the border to help with this, a gesture which led Mr Trump to postpone his threat to impose tariffs on Mexican imports until early March.

The other side of the border has been beefed up too. The US Department of Defence has ordered 1,500 additional active-duty troops there to tackle the national emergency declared by Mr Trump. Airborne surveillance has been ramped up to monitor Mexican gangs.

But it is not clear that all this military muscle will have much impact on the flow of fentanyl. A US Drug Enforcement Administration (DEA) officer, who asked that his name not be used, says he welcomes any support at the border, but that more manpower is “not a panacea”. “The cartels are ingenious,” he says. “They move drugs through cars, trucks, planes, people, tunnels, whatever.”

That ingenuity is on display in social-media posts made by Michael Humphries, the CBP official who runs the Nogales crossing-point in Arizona, which offer some sense of what the border authorities are up against. Mr Humphries documents the discovery of drugs concealed in petrol tanks and spare tyres, hidden inside hollowed-out stacks of tortillas, and slotted within the axles of lorries.

Added to fentanyl’s versatility in transit is the ease with which it is produced. “It can be done in any kitchen,” says Guillermo Valdés Castellanos, former director of Mexico’s national intelligence agency. More than 90% of the fentanyl seized in the United States is found at legal entry points like Nogales. It is primarily carried into the country by citizens of the United States, not migrants. These factors, taken together, mean that focusing on borders is necessary but insufficient to stop the drug’s flow.

That is not to say that curbing the flow of fentanyl is impossible. After increasing for years, the amount of the drug seized at the southern border of the United States fell at last in 2024, by 21% from 12 tonnes in 2023 (see chart). The number of deaths attributed to synthetic-opioid overdoses in the United States dropped in 2024 too, for the first time in over a decade, by about 30% compared with 2023. Carlos Matienzo of DataInt, a security consultancy, says these drops cannot be explained by any military deployment: rather they are down to changes in health policies, increased control over production methods and the grim reality that many fentanyl users have already died.

Ms Sheinbaum’s military deployments are more about “signalling to Americans that we’re willing to help”, says Mr Matienzo. Mr Corrales, the public-safety commissioner, agrees. He says that Mexico has not changed its strategy for combating fentanyl at all. To do more than signalling, the United States and Mexico would need to work together to undermine the drug gangs, while enacting policies to reduce the demand for fentanyl in the United States.

David Hathaway, the sheriff of Santa Cruz County, of which Nogales is the seat, says he thinks an increased military presence is both unnecessary and disruptive. Instead, “people need a change of heart,” he says. “We cannot legislate morality.” ■