Most "failed states" in Africa were never real states in the first place. They were tribes living on portions of the land they didn't completely control. Some tribes traded, others warred, but that's it. There was no larger "country".
Whites started actual cities and built roads, but even that didn't typically bring the whole country together. The country was just lines on a map.
Then the whites left, and the installed African politicians ran what was left into the ground. The country was said to be "failing" when it was just returning to what it always was.
So I guess the real "failed state" was just the friends we made along the way.