why should the US...
sell corn to our enemies,
for less than its burn value?
the corn is not eaten by humans, btw
A shocking percentage of Americans are ignorant of the distinction between dent corn and sweet corn.
Having said that, dent corn does have some human food uses—corn meal, for instance, so Mexican kvetching about tortilla prices does have some basis in fact.
As I understand, corn is more often used as livestock feed, which then becomes food for humans?
Kind of a silly thing to say. Corn is fed to livestock. It is stupid to use cropland to grow fuel.