I'm Italian and I don't think you're right.

Italy is not food self-sufficient, it relies heavily on imports of cereals, animal feed, oils, and other.

We add value up the chain (with hams, cheese, etc), but bar fruits and vegetables where we are okay-ish, we cannot feed ourselves. Its been decades that even our own pasta is made out of canadian and us cereals. We simply don't have enough, let alone we don't have good quality cereals.

On top of that, our production is super reliant on imported fertilizers and chemicals. We would borderline starve in case of isolation.