Exceptionalism is the idea that a country is different to others, and better as a result.
Brexit was powered by exceptionalism. So too is Russian aggression. So is the indifference of those in power in the USA as to the impact of their decisions on its currency on developing countries a form of exceptionalism when that currency is used by so many other countries.
Exceptionalism is based on arrogance, mythology, and straightforward lies. Its founding assumption is that there is an indigenous people who are possessed of superior traits that occupy a territory. Racist and eugenic within itself, the claim is also very obviously false. The only truly identifiable human trait is our extraordinary commonality, rather than our differences. Exceptional individuals might exist. There is no evidence that exceptional populations do, although those capable of being deceived into brutality seem to be a recurring theme of history.
The logical conclusion being that there’s no reason the indigenes should be ruling Africa. Bring back colonialism!