There is a reason that countries like South Africa would be substantially less high on that list than they used to be 25 years ago, and increasing economic -and political- isolation is definitely one of the reasons it changed.

We see in political science that the definition of nations is somewhat circular - for a country to meaningfully exist, its recognition of a significant number of other countries is almost an essential feature. This is the reason that projects like Sealand fail, and also why revolutions attract so much international meddling.