We swoop down through the clouds to the Coliseum grounds. We see senators, centurions, aqueducts, Caesar, bloody-handed Brutus, Roman baths. So far, we might be watching a cheesy educational video about ancient Rome or a really bad movie preview.
Complex human societies, including our own, are fragile. They are held together by an invisible web of mutual trust and social cooperation. This web can fray easily, resulting in a wave of political instability, internal conflict and, sometimes, outright social collapse.