That the Zim economy collapsed owing to western economic sanctions is a bare faced lie - I will assume that you repeat it out of ignorance, not malice.

There were no sanctions against the country of Zimbabwe or the Zanu PF government.

A few countries including the USA applied limited and specific sanctions against a small list of individuals and organisations.
These trade sanctions were also ludicrously easy to by-pass - one could sell products to the Zanu PF army, but not to certain ranking officers in the army - go figure.

The Zimbabwe economy collapsed as a result of the ideology and poor economic policies - especially monetary policy - of the Zanu PF government.

You are on the right track when you indicate that in thre global economy, autarchy is not a viable solution, and that the market will reward or punish governments for their policies, as the case may be.