GM Corn Dispute with Mexico

In December 2024, a dispute panel ruled in favor of the United States in its conflict with Mexico over genetically modified (GM) corn imports. The panel determined that Mexico’s restrictions on GM corn violated the United States-Mexico-Canada Agreement (USMCA) and urged Mexico to align its policies with the agreement within 45 days.

The dispute began in 2020 when Mexico announced plans to phase out GM corn imports by the end of 2024. Tensions escalated in February 2023 when President Andrés Manuel López Obrador issued a decree banning GM corn in tortillas and tortilla masa. In response, the U.S. initiated a formal dispute resolution process, arguing that the ban lacked scientific justification and violated the USMCA.

While the U.S. hailed the decision as a victory, Mexico expressed disagreement with the ruling, citing concerns about protecting the environment, native corn varieties, and biodiversity. Nevertheless, Mexican officials pledged to comply with the panel’s recommendations.

Under the USMCA, trade decisions must be based on scientific evidence, and the U.S. argued that Mexico’s policies violated provisions related to sanitary and phytosanitary measures, market access, and national treatment. Specifically, sanitary and phytosanitary measures are regulations designed to protect human, animal, and plant health from pests, diseases, and contaminants. The U.S. contended that Mexico’s ban on GM corn was not scientifically grounded and could be viewed as an unjustified trade barrier under the SPS provisions of the USMCA.

This suggests that trade policies should rely on the absence of scientific evidence rather than human history, practices, and traditions. While the impact of GM corn on biodiversity and native corn varieties remains uncertain, caution is warranted. The argument that something is not “science-based” should apply equally for and against the use of GM corn.

The ruling has significant economic implications. Mexico is the largest importer of U.S. corn, with $5 billion in exports in 2023. The decision ensures continued market access for U.S. corn producers, highlighting the growing tension between trade agreements and domestic environmental and other policies.

However, the USMCA and its predecessor, NAFTA, primarily focus on economic interests rather than health or biodiversity. The implementation of NAFTA in 1994 had negative effects on public health in Mexico, contributing to rising obesity rates. Between 1990 and 2016, obesity rates nearly tripled, coinciding with the increased availability of processed foods and sugary drinks, disrupting traditional diets and agricultural practices.

This ruling reflects the potential risks of GM corn for consumers. In Mexico, products containing GMOs must be labeled “Contiene Organismos Genéticamente Modificados.” However, enforcing labeling is challenging in farmers’ markets and small vendors. For example, tortillas made at a tortillería (a traditional tortilla shop) are not subject to GMO labeling unless packaged for retail sale.

Addressing this issue requires a broader focus on food systems and health policies. Specifically, Mexico needs to support its campesinos (small farmers), who typically practice more environmentally sustainable methods, protect native corn varieties, and address biodiversity concerns. The ruling’s reliance on sanitary and phytosanitary measures, market access, and national treatment seems more about protecting unfair market practices. As highlighted in the article “Swimming Against the Tide,” since the signing of NAFTA in 1994, Mexico has experienced a dramatic decline in its ability to grow its food. The U.S. has exported products at prices below the cost of production, gaining market access through NAFTA and later the USMCA in ways that unfairly treat Mexican farmers. In this context, the ruling is an insult to Mexico.