Something quick, something simple:
What happens when the United States of America is no longer able to export food?
Seriously, we import so much other stuff (whether directly as in Wal-Mart through China) or through subterfuge (as in our “american” cars being made in Mexico). And now we’re getting to the point where all the corn we’re using is going towards ethanol instead of feed or fuel.
What happens when we no longer can grow all the food we need, or choose not to (just as the American Elite seem to have chosen not to make anything with or by americans)?