The killing of one of the hemisphere’s most feared drug traffickers has delivered Donald Trump the kind of cross-border victory he has demanded for months.

Nemesio “El Mencho” Oseguera Cervantes — the 59-year-old leader of the Jalisco New Generation Cartel — was fatally wounded Sunday during a Mexican military operation in Jalisco state and later died while being transferred to Mexico City, according to Defense Secretary Ricardo Trevilla. Eight cartel members were killed in the confrontation.

Oseguera was one of the most wanted fugitives in the United States. The State Department had offered a $15 million reward for information leading to his arrest. The Trump administration designated his cartel a foreign terrorist organization last year.

“El Mencho was a top target for the Mexican and United States government as one of the top traffickers of fentanyl into our homeland,” White House Press Secretary Karoline Leavitt said on X on Sunday. In the same post, she confirmed the United States played a role in the operation.

The cartel leader’s death marks the highest-profile blow against a Mexican criminal organization since the recapture and extradition of Joaquín “El Chapo” Guzmán nearly a decade ago — but unlike Guzmán’s arrest, Oseguera died in a military confrontation that immediately reverberated across the country. 

It also arrives at a pivotal moment for Trump, who has spent months pressuring Mexico and its president, Claudia Sheinbaum, to intensify its campaign against cartels he blames for fueling the U.S. fentanyl crisis.

In her statement, Leavitt underscored the administration’s posture. “President Trump has been very clear — the United States will ensure narcoterrorists sending deadly drugs to our homeland are forced to face the wrath of justice they have long deserved,” she wrote.

Where Pressure Paid Off

The operation triggered a wave of coordinated retaliation across multiple states, including highway blockades, arson attacks and deadly clashes with security forces that left dozens dead. However, politically, the strike carried a different weight on both sides of the border.

In Mexico, the operation signaled President Claudia Sheinbaum's assertion of state authority. In Washington, it marked pressure from Trump translating into visible results.

For months, the White House had warned that Mexico needed to move more aggressively against cartels driving fentanyl into the United States. Trump publicly floated tariffs and even unilateral military action. His administration designated major cartels as Foreign Terrorist Organizations in August and deployed additional U.S. personnel to waters near Mexico, framing the groups as “direct threats” to national security.

"These cartels have engaged in historic violence and terror throughout our Hemisphere — and around the globe — that has destabilized economies and internal security of countries but also flooded the United States with deadly drugs, violent criminals, and vicious gangs," Sean Parnell, the Pentagon's spokesperson, told Newsweek.

The threats did not stop after the designation. Earlier this year, hours after the U.S. overthrow of Nicolás Maduro, whom Washington labeled a “narco-terrorist,” Trump said he might broaden the campaign to target Mexican drug-trafficking groups.

“We have to do something” about America’s southern neighbor, Trump told the television program Fox and Friends, noting the Mexican government had repeatedly rejected his offer to “take out the cartels.”

A week later, Washington created a new intelligence unit — the Joint Interagency Task Force–Counter Cartels (JIATF-CC) — under U.S. Northern Command. According to U.S. officials cited by Reuters, the task force compiled detailed intelligence on Oseguera and passed it to Mexican authorities ahead of Sunday’s raid.

David Mora, senior Mexico analyst at the International Crisis Group and a researcher on organized crime, told Newsweek the killing marked “an achievement for Sheinbaum and Trump on two levels.”

“One, because it shows that Mexican forces and that their security strategy can have these major operations to capture high-value objectives,” Mora said. “It’s also an achievement with the United States… the game that I propose to you works.”

Rather than American troops crossing the border, the intelligence apparatus fed information to Mexican special forces, who moved on the target. The result delivered what Washington had demanded — a high-value cartel leader removed — without breaching Mexican sovereignty.

Sheinbaum emphasized that the operation was planned and executed by Mexican forces, stating that while intelligence was shared, there was “no foreign participation on the ground.” 

The Fragmentation Risk

After winning in a landslide and maintaining high approval ratings, Sheinbaum has insisted that Mexico would not return to the full-scale “war on drugs” strategy of previous administrations. Instead, she has argued for a model centered on intelligence coordination and territorial control.

However, the challenge for Sheinbaum now is sustaining momentum without triggering a prolonged spiral of reprisal attacks while also navigating increased pressure from Trump. Even after Oseguera’s death, that pressure did not ease.

On Truth Social on February 23, Trump wrote: “Great interview with American patriot Derek Maltz, hosted by the wonderful Fox & Friends presenter Lawrence Jones, who is fantastic! Mexico must step up its efforts against the cartels and the drugs!”

Mexico’s recent history offers a more complicated precedent. Dismantling a criminal network that spans more than 20 Mexican states and much of the United States will require more than a single operation.

Research by the International Crisis Group shows that leadership removals over the past decade and a half have frequently coincided with criminal fragmentation. Between 2009 and 2020, at least 543 armed groups operated across Mexico. Municipalities affected by a kingpin capture tend, on average, to see at least one additional armed group emerge in the aftermath, according to the group’s data.

“History shows that this strategy does not solve drug trafficking or organized crime. On the contrary, it increases violence,” said Mora, senior analyst at the International Crisis Group, who has warned that high-profile removals can destabilize territories if not paired with deeper structural reforms.

“It may sound good and grab headlines, but it would be an empty victory,” he added.

The wave of coordinated retaliation that followed Sunday’s operation — including more than 80 highway blockades and dozens of reported deaths, among them members of Mexico’s National Guard — has reinforced those concerns among security analysts.

“As with other episodes of violence and displacement, it is not unthinkable that these communities could migrate to the border and seek asylum in the U.S. This would disrupt the orderly migration process the Trump administration has sought,” Cecilia Farfán-Méndez, head of the North American Observatory at the Global Initiative Against Transnational Organized Crime, told Newsweek.

Mora echoed those concerns, adding that the political difficulty for Mexico’s president will be managing bilateral cooperation under mounting pressure while avoiding a repeat of earlier cycles of fragmentation and violence.

“Removing a leader is one thing,” Mora said. “Preventing what comes next is the real test.”