Mexico is not only dangerously dependent on US growers for its most important staple crop; it is growing more and more dependent by the year. Mexico’s government wants to reverse this dynamic, but the US has other ideas.

Mexico’s government recently unveiled plans to impose a temporary 50% export tax on white corn, a staple food in the country, which will remain in effect until at least June 30. Mexico is fully self-sufficient in white corn but depends on the US for much of its supply of yellow corn. The government said the move was necessary to guarantee supply and price stability of the staple, but it almost certainly also forms part of the government’s broader campaign to reduce Mexico’s dependence on US imports of GMO food, in particular corn.

“The supply and production of white corn in our country are important factors in determining its price and, therefore, of the various consumer products made from it,” the decree published in Mexico’s official gazette said.