The deal reached this week by President Donald Trump and Mexican President Claudia Sheinbaum to postpone implementing tariffs appeared to be largely focused on stopping the importation of the synthetic opioid fentanyl — a goal that is of particular interest in San Diego and Baja California.
Nearly all of the fentanyl that arrives in the U.S. from Mexico does so through ports of entry in San Diego County, Imperial County and Arizona. From the last few months of 2021 until this past December, more than 44% of all the fentanyl seized by U.S. Customs and Border Protection officers was seized at ports of entry along the California border, according to CBP data. Seizures at ports of entry along the Arizona- Mexico border accounted for another 52%.
On Monday, Trump and Sheinbaum announced that 10,000 members of the Mexican National Guard would be deployed to the border as the key part of the deal delaying the tariffs. Both wrote on social media that the National Guard’s main goal was to combat fentanyl smuggling.
But how, exactly, the troops might help stop the flow of fentanyl remains unclear. Unlike undocumented immigrants, who might favor scaling a border fence or following smuggling routes in remote areas to avoid detection, fentanyl and other drugs almost always enter the U.S. in vehicles driven by U.S. citizens through designated ports of entry.
“There’s a fairly obvious reason for that — drugs are heavy,” said Owen Roth, an attorney who recently left the San Diego U.S. Attorney’s Office after more than six years leading large-scale, multi-defendant drug prosecutions.
Ports of entry are already staffed by CBP officers with the ability to conduct inspections and who are often supported by U.S. military and California National Guard troops. But on Thursday, Mexican federal agents, including National Guard troops, conducted an unusual checkpoint on the Mexican side of the San Ysidro Port of Entry, randomly inspecting some vehicles for drugs and conducting searches with the assistance of drug-sniffing dogs.
Roth said Mexican authorities conducting those types of pre-inspections would face the same main challenge as CBP officers.
“The amount of traffic is so significant, there’s a serious question if they’d make a dent — and whether that would live beyond this surge and this enforcement period,” Roth said.
Saúl Sandoval, a professor of politics and economics at CETYS University, a private college in Baja California, also expressed doubt about how much the National Guard can accomplish in the one month that the nations agreed to pause the tariffs.
“Since 2019, we’ve seen troops being sent to the border to stop illegal crossings, but the number of migrants and the drugs flowing into the U.S. didn’t decline,” Sandoval said. “So I wonder if there is a correlation between more troops and less flow of migrants and drugs. I’m a little skeptical about whether in one month we will see major accomplishments.”
How fentanyl arrives
Since the start of fiscal 2022 up until this past December, CBP officers at all U.S.- Mexico land ports seized 57,843 pounds of fentanyl, according to CBP data.
During that same time frame, U.S. Border Patrol agents in the same general areas along the border seized 8,345 pounds of the powerful synthetic opioid. Border Patrol agents monitor the areas between ports of entry but also operate highway checkpoints, where they seize drugs that could have crossed the border in numerous ways, including through ports of entry.
In fiscal 2022, 89% of convicted fentanyl traffickers were U.S. citizens, according to data analyzed by the Cato Institute, a libertarian think tank.
Because fentanyl is so powerful, smaller loads that are harder for authorities to detect can still be valuable for drug-trafficking organizations. But still, most traffickers attempt to get larger quantities across the border.
Roth, who recently launched a defense and plaintiffs’ firm with his wife, longtime defense attorney Danni Iredale, said some pedestrians at ports of entry smuggle fentanyl strapped to their bodies.
“But body carriers can only move a minuscule amount compared to cars,” Roth said. “It’s usually measured in grams, or at most a kilogram or two.”
Even more rare is for migrants or drug couriers to try to cross a border fence or some other area away from a port of entry while carrying drugs.
“In my anecdotal, decade-long experience I have not seen any cases where people were crossing the border carrying contraband other than at designated points of entry,” Iredale said.
Roth said migrants often struggle to carry just the items they need for survival while also trying to travel quickly and avoid leaving footprints that could tip off Border Patrol agents. Drug smugglers traveling by foot, even if they don’t intend to stay in the U.S., would face similar problems.
“Hauling 75 pounds of cocaine is not an effective strategy,” Roth said. He added that neither he as a former prosecutor nor Iredale in her defense practice in San Diego “have ever handled such a case or heard of such a case.”
Recent National Guard deployments
Mexico positioning troops along the U.S. border is nothing new, though the forces have typically been deployed for immigration purposes. In December 2023, Mexican officials installed a chain link fence, reinforced with razor wire on top and bottom, near a section of the Tijuana River channel that had become a main point for migrants attempting to enter the U.S. in San Ysidro. National Guard troops and immigration agents were stationed behind the fence to keep watch.
Last year, a few months after the fence was erected in Tijuana, Mexican officials set up inspection camps just south of the East County desert community of Jacumba Hot Springs. The inspection camps were set up near areas where there are gaps in the border fence and where asylum seekers had for months been crossing into the U.S. and surrendering to Border Patrol agents. The camps on the Mexican side of the border were staffed with immigration agents and soldiers from the Army and National Guard.
“The camp’s purpose is deterrence,” David Pérez Tejada, head of the migration institute in Baja California, acknowledged last February. “For the Mexican government, it’s also about containment, that’s the most important thing. What we want is to prevent (migrants) from falling prey to organized crime.”
During Trump’s first term in 2019, he made a similar deal with Mexico to the one made this week. In 2019, he proposed tariffs but then suspended their implementation when former Mexican President Andrés Manuel López Obrador agreed to deploy thousands of National Guard troops to the border and elsewhere across the country. Those troops were focused on limiting the arrival of migrants rather than drugs.
Sandoval, the CETYS professor, said the 2019 deployment and additional deployments since then have had little impact on the arrival of migrants or the flow of drugs, which he said are both “institutionalized” issues that date back decades and can’t be quickly or easily solved.
Gen. Laureano Carrillo, head of the Baja California Civil Security Secretariat, said Thursday that about 3,000 National Guard troops have been assigned to Baja California. He said the National Guard will have a presence at ports of entry and along the border fence.
The troops will patrol, work in coordination with state and local police and may set up camps in some areas if needed, Carrillo said.
Mexican officials confirmed that the pre-inspections being conducted Thursday near the San Ysidro port by National Guard troops and other federal agents were part of Sheinbaum’s border security plan announced Monday. The checkpoints could be held on a sporadic basis, officials said.
The troops deployed this week were previously stationed in southern and central states across Mexico, according to El Universal, a Mexican news outlet. El Universal reported that 1,949 of the troops would be stationed in Tijuana, 500 in Tecate and 561 in Mexicali.
The challenge ahead
Roth said one of the reasons the Mexican National Guard might have trouble targeting fentanyl specifically is that Mexican drug-trafficking organizations move many types of drugs, often in combination with each other. He said people caught smuggling drugs through ports of entry often don’t know which type they’re smuggling and are typically caught with two or more varieties of drugs in their vehicles.
“So the challenge for the National Guard can’t be defined as bringing down fentanyl — they can only target all the drugs and hope for the knock-on effect of bringing down fentanyl,” Roth said.
The prosecutor-turned-defense attorney also questioned the general effectiveness of the National Guard, which Mexico created in 2019. “Relatively speaking, it’s a brand new force with little experience, compared to the Mexican Army and Navy, in dealing with complex drug trafficking issues,” Roth said.
He said one way the National Guard might get the “best bang for its buck” at the border is by going after drug tunnels or maritime drug smuggling routes instead of conducting pre-inspections at ports of entry.
But Roth argued that any effective anti-drug campaign can’t focus just on the border and must include long-term investigations and intelligence operations aimed at dismantling cartels.
“It runs deep,” Roth said. “You can deploy to the border, that’s fine, but that doesn’t go to the root of the problem.”
Sandoval agreed, saying the National Guard was unlikely to have success “unless the Mexican government continues to target the root cause of the problem in Sinaloa” and other areas where fentanyl and other drugs are produced.
Staff writer Alexandra Mendoza contributed to this report.
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