A view of a section of southern border wall, left, on an evening in Nogales, Arizona. Faced with increasing pressure from both from both the Mexican and US governments, the Sinaloa Cartel continues to adapt - shifting to smaller loads of drugs, devising creative methods, and adjusting in real time to changing threats. Photo / Adriana Zehbrauskas, The New York Times
The fentanyl packer moved with precision, his headlamp casting a sharp glow on the swift work of his gloved hands.
Hoodless carcasses of old vehicles sat gutted under a pitch-black sky. Car jacks, coils, and greasy rags littered the ground.
The man sprayed six aluminium-wrapped packets with a liquid that smelled like chlorine, a compound that he said would help disguise fentanyl from search dogs.
Underneath the foil, the deadly drug was wrapped in carbon paper to try to avoid basic methods of X-ray detection, he said.
The 58-year-old man, a mechanic by day and drug packer by night, had been working for the Sinaloa cartel for more than 20 years, fixing and loading cars with cocaine, meth, and now fentanyl.
In all of that time, he said, his job has never been as dangerous as now. “Hopefully this is my last gig,” he said.
The cartel, which as one of the world’s most formidable drug syndicates had once seemed immune to challengers, has been pushed into survival mode.
United States President Donald Trump has vowed to crush the fentanyl trade — directing the Pentagon to begin using military force against certain cartels that his Administration considers terrorist organisations.
Mexico, pushed hard by Trump, has launched its own aggressive crackdown, deploying hundreds of troops to combat the Sinaloa cartel, a US-designated terrorist group. While under intense pressure from both governments, the cartel has also been plagued by infighting.
Even in that weakened state, the cartel continues to adapt.
Its smugglers are shifting to smaller loads, devising creative methods and adjusting in real time to changing threats — showing how extraordinarily difficult it would be for any government to dismantle such an entrenched criminal organisation.
And despite the campaign against them, cartel operatives said they had no intention of giving up the trade.
Most expressed no compunction over the devastating toll in the US, where fentanyl has fuelled an addiction crisis and become a leading cause of death.
Those operatives said that they were simply running a business and argued that if they did not meet the American demand, someone else would.
The New York Times interviewed five operatives of the cartel. They spoke to the New York Times on the condition of anonymity because they would otherwise be subject to arrest or danger.
The reporting included documenting how fentanyl packages were hidden in cars in Culiacan, in western Mexico, in order to show in greater detail how fentanyl trafficking unfolds.
A car’s subsequent journey into the US was reconstructed through interviews with the five operatives: the mechanic, a driver, a high-ranking cartel member, and two traffickers based in Arizona.
The mechanic was hired this time to conceal about 6kg of fentanyl bound for the US — worth as much as US$90,000 ($151,000), but a small cargo compared with recent years, he said.
He had carved out a hidden compartment behind the panel of a car’s front left door.
He welded a steel tube between the outer shell and the interior frame, creating a false space where packages could rest. He designed it carefully: If officers knocked, seeking hidden contraband, it would sound hollow, just like a normal, empty door.
The cartels typically use midsize cars like Hondas, Nissans or Toyotas, reasoning that the more ordinary the vehicle, the more likely it would go unnoticed, the mechanic said.
He never does the same concealment twice, he said, varying it by car and quantity of contraband.
“Sometimes we place it inside the gas tank, others, under the hood by the engine, or even underneath the rocker panel,” he said, pointing at different parts of the vehicle.
The drug packing was just the start of a journey that took the car from a cartel stronghold in Mexico across the border and into the US, a trip that would require careful co-ordination by the smugglers.
Responding to the threats against it, the cartel has drawn from deep cash reserves, slashed payrolls, taken fentanyl production out of its home state, redirected shipments to Europe and — perhaps most tellingly — forged a fragile alliance with a competing organisation that was once its arch enemy.
The moves are desperate, analysts say, but they also reveal something else: a criminal network that, even in retreat, has shown a capacity for resilience and innovation.
Under these new conditions, producing and moving fentanyl has become slower, riskier and far more costly, the five cartel operatives said. Bribes now cost more, military checkpoints have multiplied across Mexico and US border agents have tightened scrutiny. More shipments are seized, so to minimise losses, traffickers are sending smaller quantities.
Yet the cartel operatives said the demand for fentanyl had not waned, despite its role in huge numbers of overdoses every year. So the cartels find ways to deliver the drug.
The operatives’ descriptions of how the fentanyl was smuggled across the border were consistent with the methods described to the New York Times by US law enforcement officials, including one overseeing border operations and another who monitors cartel activity.
Findings by the Drug Enforcement Administration, described in the agency’s reports, also match the smuggling techniques described by the cartel operatives.
The mechanic, whose own life in Mexico’s underworld had left him with serious gunshot wounds, a cocaine addiction, and a shattered family, was among the few to express guilt for his actions.
Fentanyl, he said, “is the reason for this damn war where so many people have died, many of them innocent, and that weighs on me”.
“I am scared, really scared,” he added, “because not everyone gets out of this, and the ones who do, they leave feet first.”
The Driver
For the mission from Culiacan, cartel leaders were having trouble finding reliable men. Too many had been arrested or killed in the bloody cartel infighting and Mexico’s offensive to dismantle the criminal group.
One high-level operative, whose role focused on recruiting chemistry students to help manufacture fentanyl and overseeing production, typically avoided risky hands-on operations like this.
But despite his rank, the cartel’s needs put him at a crossroads. He could stay behind the scenes, or seize a dangerous opportunity to impress his superiors.
He did not hesitate, taking the chance to prove himself — and to become an even closer partner in the multimillion-dollar business.
He said he could gain not only money or a possible promotion, but the rarest commodity, as well: trust from the cartel’s upper ranks, in a world where suspicion alone can be fatal.
To gain that trust, he was willing to risk his freedom and his life.
So, on a recent night, he turned the car’s key and set off towards the US border, he later recounted.
A second vehicle moved ahead of him, holding lookouts trained to read the terrain.
Their job was to call out what lay ahead and spot potential threats: a new checkpoint, soldiers where there had been none, a car parked too long on the side of the road.
“They watch for anything,” the driver said. “Anything suspicious.”
He followed at a distance, his hands tight on the wheel, an assault rifle tucked beneath the seat, he later recalled. The destination: Arizona.
There would be no turning back — not if they got stopped, not if someone got spooked. The cartel’s retaliation would be swift. But the payout was worth it, he said.
Hours after setting off, he said, he was instructed to stop. He waited for hours more at a midpoint on the route north.
The journey from Culiacan to the US border was a meticulously choreographed operation.
A single driver took a car packed with the synthetic opioid but backing him up was a robust machinery of power.
At each stage, the driver received instructions from higher-ups — coded guidance on which roads to take and which to avoid.
Sometimes, he drove along well-paved highways, cartel operatives said. At other times, he veered onto dirt tracks snaking through brush.
The path was never improvised. Each detour was designed to sidestep law enforcement or military checkpoints.
Even those checkpoints were accounted for. According to the five operatives, bribes are usually arranged at no fewer than four Mexican military posts between Sinaloa and Sonora states.
Soldiers wave the designated driver through with the cargo untouched — the price of passage already paid, they said.
At one point, the driver recounted, progress was halted by a Mexican military “checkpoint that wasn’t there before.” The cartel then had “to solve that little problem” with a bribe, he said.
The Border
Just as he was closing in on his destination, he said, a call came in: stop the car.
Roughly 110km south of Tucson, Arizona, on the outskirts of Nogales, Mexico, the driver pulled over for what had become a routine pause on these runs.
On both sides of the border, a network of lookouts and co-ordinators was working in sync, double-checking that every piece of the operation was in place.
That included the most critical one: the US border agent who, for a price, had agreed to let the vehicle through, cartel operatives said.
But soon, notice came from the US border agent that there was trouble, the driver said. The car had been flagged.
Word spread quickly through the network that US authorities had been tipped off, possibly by a cartel rival. The operation was compromised. The smugglers activated a Plan B.
A second vehicle would be arranged deeper in Sonora, the cargo repacked.
But that wasn’t the only issue. US security looked tighter amid tensions in the Middle East. Nothing was moving easily.
So the waiting began.
As hours dissolved into days, anxiety crept in. The driver thought about turning back and driving south to Sinaloa. But pulling out meant risking retribution.
After three days in limbo, another signal finally came. The operation was back in play.
Once again, the cartel’s network had kicked into motion — a criminal ecosystem sustained by a co-ordinated web of lookouts, drivers, packers, operatives and a long chain of corrupted officials, from street-level foot soldiers to border agents.
The driver said that the US border agent would now receive tens of thousands of dollars for the warning alone, on top of the original payoff already promised for waving the car through the Mariposa Port of Entry in downtown Nogales.
His accusation could not be independently verified. But the driver and the mechanic both said the drugs had made it across the border — a sign of how deep the cartel’s reach ran.
The US border agency, Customs and Border Protection, refers cases of possible corruption in its ranks to the Justice Department for investigation.
Asked about accusations of agents taking bribes, the agency’s acting commissioner, Rodney Scott, said in a statement that “CBP agents and officers risk their lives to defend you every day”.
The operative’s account also corresponds with findings by US authorities who have documented the Sinaloa cartel’s influence.
In April, a former US Border Patrol agent was convicted of conspiring with two Mexican nationals to let vehicles pass through his lane without inspection, the US Attorney’s office for the district of Arizona said in April.
Federal prosecutors said the agent provided details to the Mexican individuals about checkpoint operations and cleared at least five vehicles in exchange for a promised cut of the smuggling fee — US$20,000 of the US$40,000 that the traffickers received.
The cartel exerts “near-total control over the border region south of Arizona, giving the cartel easy access to the San Luis Rio Colorado and Nogales points of entry”, according to a 2024 DEA report. Criminals use that control to smuggle fentanyl into the US, it added.
Speaking in a phone interview once he was back in Mexico, the driver said that he had delivered the cargo in Tucson and that local operatives would take it to California.
The driver said everything had gone smoothly because of how it had been arranged. “The crossing was easy,” he said.
This article originally appeared in The New York Times.
Written by: Paulina Villegas and Maria Abi-Habib
Photographs by: Adriana Zehbrauskas
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