By contrast to the model of the two World Wars, as well as to
imagined models of
global nuclear holocaust, the actual face of warfare since 1945 has been that of civil wars and regional armed
conflicts.
In the case of WW1, where white swans represent the persistence of peace, and black ones an outbreak of
global conflict, black swans had existed before in the form of the Napoleonic Wars, so the question of
imagining them doesn't really arise.