MEXICO CITY — Relations between Mexico and the United States have entered one of their most difficult periods in a century, marked by a sharp shift in Mexico's diplomatic strategy. President Claudia Sheinbaum, who previously described her approach to U.S. President Donald Trump as a "cool head," has not used that phrase since March — a silence her allies and critics alike read as a hardening stance.
Rafael Fernández de Castro of the University of California, San Diego, said Sheinbaum's rhetoric has moved from stoic cooperation to direct defiance.
Security has become the sharpest point of friction. The Trump administration has expanded its pressure beyond demanding a crackdown on drug gangs to targeting Sheinbaum's political allies. In April, the United States indicted Rubén Rocha Moya, then-governor of Sinaloa, on drug-trafficking charges. Rocha Moya denies any wrongdoing.
Rocha Moya has close ties to Andrés Manuel López Obrador, the founder of Morena, Sheinbaum's political party. More than 50 Morena politicians have had their American visas revoked, a signal of a broader U.S. pressure campaign.
Mexican citizens have grown increasingly suspicious of U.S. security operations on Mexican soil. That concern intensified in July when the FBI publicly displayed the aircraft used to transport gang boss Ismael "El Mayo" Zambada from Mexico to the United States in 2024. Mexico's government had received assurances that U.S. agencies played no part in Zambada's capture. After the FBI's display, Sheinbaum launched an official investigation. She has also refused to extradite Rocha Moya, with Mexico's courts considered unlikely to convict him.
Migration, previously a less contentious issue, has become another source of friction. Since Trump returned to office in January 2025, Mexico has helped Washington sharply reduce illegal border crossings. But a fatal incident on July 7 escalated tensions.
An Immigration and Customs Enforcement agent shot and killed Lorenzo Salgado Araujo, a Mexican national who had lived in the United States for 35 years, during an operation in Houston. Salgado Araujo was not the intended target. His death was the 17th killing of a Mexican citizen in ICE custody or operations since Trump returned to the White House.
Two days after the Houston shooting, Sheinbaum announced her government would pursue criminal charges in American courts for the killings of Mexican citizens whose "only crime is working honestly in the United States."
Trade relations have also soured. Sheinbaum had sought an extension of the USMCA, the North American free-trade pact, beyond its current 2036 expiry. On July 1, Trump refused, meaning the agreement will now undergo annual review — introducing significant uncertainty for both economies.
Lila Abed of the Inter-American Dialogue, a Washington-based think tank, said Sheinbaum had heavily relied on securing that extension after making concessions to Trump. The refusal hardened Mexico City's position further.
At public rallies, Sheinbaum has told crowds: "We will always hold our heads high. Mexico is a free, independent and sovereign country. We coordinate, we collaborate, but we do not submit."
The approach has resonated at home. Polls show most Mexicans approve of Sheinbaum's handling of the bilateral relationship, and Trump's actions have driven a surge of nationalist sentiment across the country.
