Might, of course, depend on rivers too.
Rhodesia was reliant on blockade breakers for many things, but prospered due to its agricultural success in being able to feed its people and supply to others. Zimbabwe was not blockaded but decimated its agricultural heritage and is trying to fool the world that it is not on the verge of a criminal famine in a (more or less) self-sufficient land.
Other African countries have been overshadowed by their bigger neighbours – whether land-locked or not.

Flood.™