No we could not. That subsidized introduction of available food would shift the whole demand curve. Farmers currently produce as much food as the market demand

No we could not. That subsidized introduction of available food would shift the whole demand curve. Farmers currently produce as much food as the market demands, plus some excess capacity is converted biofuels. If the market required less, they would (eventually) produce less unsubsidized food. Then, the logic goes, WW3 takes out a lot of our food and we suffer massive shortages because there is no extra capacity to produce more.