US should challenge Mexico’s ban on glyphosate and genetically-modified corn at the WTO

On New Year’s Eve, Mexico’s president, Andrés Manuel Lopez Obrador, issued a decree that has U.S. agriculture worried. The decree bans glyphosate, a herbicide, as well as genetically-modified (GM) corn. Since Mexico is the largest export market for American corn products, U.S. agriculture is weighing whether to ask Washington to file a trade dispute under the U.S.-Mexico-Canada Agreement (USMCA).

The U.S. should file a case, but not at USMCA. Rather, the U.S. should take its case against Mexico to the World Trade Organization (WTO). That’s because this dispute is bigger than just glyphosate, GM corn or market access to Mexico. Washington needs to unblock the appellate body and fight for science-based trade on the WTO’s much bigger stage.

Mexico’s decree is no model of clarity. It includes six articles, but the heavy lifting is done by three of them. Article 2 says that the federal government will “refrain from acquiring, using, distributing, promoting and importing glyphosate or agrochemicals that contain it as an active ingredient.” Article 3 nods to the fact that glyphosate is used by Mexican agriculture, and thus promises to deliver “sustainable and culturally appropriate alternatives.” Finally, Article 6 sets out that the federal government will “revoke and refrain from granting permits for the release into the environment of genetically modified corn seeds.” All of this is supposed to happen by 2024.

Why is Lopez Obrador doing this? The decree explains its objective thusly: “achieving self-sufficiency and food sovereignty.” In other words, it’s trade protectionism. The Consejo Nacional Agropecuario de México, which represents the country’s agribusinesses, claims that Mexican food chains will collapse without U.S. imports. The group estimates, moreover, that banning glyphosate could result in as much as a 45 percent decline in Mexico’s agricultural output. The payoff for Lopez Obrador is that the decree is expected to curry favor with rural farmers, who put their electoral weight behind him in Mexico’s last election.

How is this a trade dispute? Science, or more accurately, the lack of science on which the decree is based. Mexico says glyphosate is a carcinogen, and that GM corn puts Mexico’s native corn at risk. But Mexico can’t scientifically back any of this up, at least not in the way USMCA or the WTO would demand in litigation.   

The decree offers the “precautionary principle” as its justification, but references the Rio de Janeiro Earth Summit in this regard, not USMCA or WTO law. Both permit the use of a provisional measure if the science is “insufficient.” But even these must be based on science that exists, and constantly updated in the course of proactively gathering new science.

But Mexico has science. The country’s Interdepartmental Commission for Biosecurity of Genetically Modified Organisms reports that between 2005 and 2019, it issued 671 permits on GM products, including 202 on corn. Moreover, from 2009 to 2013 the government authorized 177 projects to research and experiment with GM corn. Mexico soured on GM corn in 2020, but this was because the government decided to boost domestic production, not because of health and safety concerns.

Mexico’s Plan B is to concede it does have science, and that this science supports a ban. It’s true that the World Health Organization’s International Agency for Research on Cancer said that glyphosate is “probably carcinogenic to humans,” but this reflected the institution’s hazard approach to the issue. A hazard approach just evaluates the possibility of harm. USMCA and the WTO demand a risk-based approach, which involves gauging the probability of harm under real-world conditions.

There are some good reasons to file this case at USMCA. For one thing, USMCA is more instructive about the procedural and substantive issues involved in formulating science-based health and safety standards than the WTO. USMCA also has deeper notification requirements. But a win at USMCA would only get the attention of Mexico and Canada, whereas a win at the WTO would deter similar efforts on glyphosate and other herbicides in countries such as Thailand, Vietnam and France, all of which have considered, or implemented, bans. Other countries are watching.

Even if Mexico doesn’t comply, the U.S. would benefit from filing at the WTO for three reasons. First, Mexico will have to explain the workings of its GM regime and explain the differential treatment of corn versus cotton, soybeans and wheat. Second, glyphosate is up for renewal in the European Union in 2022, and Europe is debating criteria for a hazard approach to this and its broader regime for endocrine disruptors. And third, it would add political heft to the litigation that Mexican agribusinesses are expected to file in domestic courts.

There’s just one problem. The U.S. is blocking appointments to the Appellate Body. This means that if Mexico were to appeal a U.S. win – as it surely would – the verdict would languish after the first ruling. In this case and others to come, an important way to make U.S. agriculture “whole” again is for the Biden administration to take up WTO reform.

Marc L. Busch is the Karl F. Landegger Professor of International Business Diplomacy at the Walsh School of Foreign Service at Georgetown University, a nonresident senior fellow at the Atlantic Council and host of the podcast TradeCraft.