“There is a pattern that we see recurring throughout history… When survival is no longer at stake, selfish elites and other special interest groups capture the political agenda. The spirit that ‘we are all in the same boat’ disappears and is replaced by a ‘winner take all’ mentality. As the elites enrich themselves, the rest of the population is increasingly impoverished. Rampant inequality of wealth further corrodes cooperation. Beyond a certain point a formerly great empire becomes so dysfunctional that smaller, more cohesive neighbors begin tearing it apart. Eventually the capacity for cooperation declines to such a low level that barbarians can strike at the very heart of the empire without encountering significant resistance. But barbarians at the gate are not the real cause of imperial collapse. They are a consequence...”

- Peter Turchin