borrowing from non-state lenders is neither a necessary nor sufficient condition for ‘autarky’ and your reasoning seems to just be since it happened in South America in the 60s it must be part of the economic mismanagement that occurred there.

i agree that our protectionist policies are bad and autarkic in nature

Like every other country. You exchange good or services for currencies from the other countries, and then you can use that currency to buy things from anybody that would take that currency.

There is nothing saying a socialist country can't produce goods and services, and sell them.