Barbarians at the Gate
I was first made aware of this historical thesis when Jacob Bronowski discussed a very similar concept in "Ascent of Man," relating it to the harnessing of the horse. The juxtapositioning of horses and tanks in the film was striking.
A barbarian in history was normally someone who, rather than being productive himself, lives by looting the productivity of others. The modern ones seem to be just simply intent on destruction.