I don't think the commenter is proposing banning exports of food to the rest of north america or other US territories (the non continental us territories/states

I don't think the commenter is proposing banning exports of food to the rest of north america or other US territories (the non continental us territories/states are too small to even be important). The exports to be concerned about the ones going to non-North American areas, especially alfalfa. I don't want people in developing nations to starve, but the truth is the current agricultural output is unsustainable which is bad for global food security in the long run.