No. Without a nuclear explosion, our country can and will feed its people. To think otherwise is a joke. I can't and don't believe that 50% of the homes would stay vacant while 50% of the people lived on the street without the government stepping in. We can house everyone now, so why would that change unless the banks boarded up the houses and had the money to stay solvent. Otherwise the govenment would take them over and then nationalize the homes. We live in a government that still is a little responsive to the public.
We also have the ability to become self sufficeint if necessary. Most nations in the world don't. Things would be tough and a lot would change, but we could do it.