The suspicion I have about self sufficiency pessimism is that it's an apples to oranges comparison. Are there any modern analogies? As near as I can tell, it hasn't been required after the 16th century, due to access to relatively timely transportation.
And if it hasn't been required, then how are we to look at existing practice and say we're bad at or incapable of it?
And if it hasn't been required, then how are we to look at existing practice and say we're bad at or incapable of it?