Brown’s Law of History: History doesn’t repeat itself. It just gives pop quizzes to see if you were paying attention.
This article by Dominic Sandbrook is perhaps a bit alarmist, but it’s not outside the realm of possibility. Anyone who has studied much history knows that the most terrible, unthinkable things do sometimes actually happen. Citizens of the West today are fat and complacent, but not immune to the same tragedies that have befallen fat and complacent civilizations many, many times before.