In the transient case, yes, because the nation only has a few months worth of food stores (JIT you know). We have plenty of productive land that can be converted to food production, but whether the tooling, knowledge, labor, and distribution exists to make that change under the duress of chaos is unknown.
Comparative advantage has its unaccounted and socialized risks.
National security starts with food security, but is founded in human relationships based in a common morality. Somebody taught us how to manage that risk 3,500 years ago, but nobody seems to have listened.
tooling, knowledge, labor, and distribution exists
I am of the opinion that we don’t have the above and you left out financing.
The American farmer’s average age is 57 and farmers really need apprenticeships rather than a formal education. It is hard to impossible to grow up in a city and decide to farm, even if you have the financial backing. It is even hard to come from another part of the country and try to farm, you have to learn what works with each crop, the land and the water.
I’ve seen many who tried and many who failed. One notable example was the guy who inherited 7 Million and within less than 7 years was broke.