The purpose of this brief article is to assess the current controversy over Genetically Modified Organisms (GMOs) in agriculture and its potential implications for the global trading system. More importantly, it offers a solution to the serious potential for injury to this system, to be developed below. The remainder of this article is divided into three sections. The next section will discuss labeling of GMO agricultural products, distinguishing between issues of food products and those affecting seed. Next, it will argue in favor of a particular type of "negative" label ("this product contains no GMOs") as distinct from a "positive" label ("this product may contain GMOs"). This proposal draws on the U.S. experience in the dairy sector with milk from cows treated with recombinant bovine somatotropin, or rBST. Finally, it concludes with a discussion of issues which are left unresolved by the labeling proposal, and some of the remaining challenges posed by GMOs for the global food and agricultural system.