Assigning responsibility and agency to state policies for agriculture and targeting self-sufficiency would work quite poorly in today's world. The modern world

Assigning responsibility and agency to state policies for agriculture and targeting self-sufficiency would work quite poorly in today's world. The modern world is fed by growing stuff in places where it grows best, and trading food for other stuff. This also provides robustness against localized crop failures. (And sadly feeding most of that to badly treated farm animals...)