The Deep Roots of Mexico’s Trade Dispute With U.S. Over GMO Corn

The history of the current dispute between Mexico and the U.S. over genetically modified corn has roots much deeper than the presidential decree that set it off. Opposition to GMO crops in Mexico has simmered for 20 years, born of worries that ancient landrace varieties of corn that are central to the country’s social, cultural and economic well-being would be lost.

In late 2020, when Mexican President López Obrador mandated the phase-out of GMO corn by 2024, he was in part fulfilling a campaign promise to those opponents. The president vowed to replace GMO corn with “sustainable and culturally appropriate” alternatives. But the decree, which also would ban the use of the controversial weedkiller glyphosate, alarmed U.S. farmers, who grow mainly GMO corn and sell much of it to Mexico. They and their allies in Congress urged the Biden administration to hold Mexico accountable under United States-Mexico-Canada Agreement (USMCA).