They said it couldn't happen. It was all supposed to be locked up tight and under control. Yet, despite all the assurances to the contrary, unapproved genetically modified wheat has been found in an Oregon wheat field, and the implications of its discovery are far-reaching and potentially devastating. Monsanto (NYSE:MON) may have just single-handedly wrecked the wheat industry and the economy.

Corn, soy beans, alfalfa, sugar beets. All these crops have been genetically modified by Monsanto and its GM brethren to the point where there are virtually no alternatives for farmers. GM corn accounts for 86% of the country's supply. More than 90% of the soy beans have been altered. Sugar beets are half the country's sugar supply, and 95% of those seeds are from Monsanto.

All told, Monsanto, DuPont (NYSE:DD), and Syngenta (NYSE: SYT) control 53% of the world's seed production, yet their control of our food supply is almost all-encompassing, because they cross-license their technology between themselves and with other companies.

Monsanto recently agreed to share its technology with Dow Chemical (NYSE:DOW) and Bayer (and vice versa), while DuPont and Bayer similarly expanded their collaboration. Syngenta is cross-pollinating Dow's AgroSciences division with its GM technology.

Yet, the one crop that has been saved from being altered up until now has been wheat. Not that Monsanto hasn't tried, as it experimented with modifying its DNA to make it resistant to its Roundup herbicide. Fields in 16 states including Arizona, California, Florida, Nebraska, and Oregon were used to test Roundup Ready wheat seed. But because the rest of the world has banned GM wheat from their bread boxes, Monsanto backed off, and suspended the program in 2005.

The wheat strain discovered last month was in a field that was supposed to remain fallow. Instead, it sprouted, and was found to contain the Roundup Ready gene, even though the Agriculture Dept. supposedly destroyed all the seed that was tested except for a small amount it kept to run additional tests. Now we learn that some managed to escape.

The U.S. is, by far, the world's largest exporter of wheat, shipping almost 28 million metric tons around the world, or about half of all the wheat this country produces each year. That's just as much as all of Europe and Canada combined! Countries like Japan and South Korea are huge importers of U.S. wheat, but it's done on one condition: the wheat can't be genetically modified.

In the wake of the discovery of this supposed rogue GMO strain, Japan began canceling wheat imports, and so did South Korea. Both Taiwan and Europe are stepping up their monitoring of imports with an eye toward suspending them if genetically modified wheat is found. With 90% of the wheat from Oregon, Washington, and Idaho earmarked for export, the emergence of a GMO strain could cripple the market for it and, thus, the economy.

While officials immediately proclaimed it an isolated incident, how do they know that? They can't even say how it got into the field in the first place, but we're supposed to believe it's not widespread. 

While Monsanto speculates it could be "sabotage," with the toothpaste out of the tube, it's easy to devise an equally sinister explanation, one that actually benefits Monsanto. Sure, foreign countries would initially reject U.S. exports of GM wheat; but where would they turn to make up half of the world's supply? And when it becomes a choice of feeding their people or starvation, it may ultimately lead to acceptance of genetically modified wheat. And once that happens, Monsanto controls the world's wheat supply. Tinfoil hat brigade stuff to be sure, but no more outlandish than Monsanto's supposition.

Despite assurances that GM foods are safe to eat, this latest incident underscores why it's so important that such foods are labeled that they've been altered at the molecular level. Individuals should have a choice as to whether they ingest GM foods or not, but Congress has seen fit to protect Monsanto at every turn by keeping consumers in the dark.

When it comes to the nation's bread basket, this country's wheat supply and its economy need to be saved from Monsanto.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.