>The notion is that the history of European colonialism and imperialism "justifies" black and Chinese nationalism as a countermeasure to white supremacy.

One could equally well point the the anti-colonial resistance in the Balkans and the Caucuses against Ottoman imperialism. The result of which were massacres and genocides up until 1925. You could still buy white sex slaves in Istanbul in 1915: https://en.wikipedia.org/wiki/Slavery_in_the_Ottoman_Empire#...