It’s an old cliche that the republic died because people lost their faith in the republic, but maybe it only lived for so long because it was able to inspire entire generations of legislators, civil servants and generals willing to fight for it.

Civic pride is a hell of a drug. People are willing to endure, and undertake, horrific things as long as their associate their own identity with the polity, and the polity responds in a way that they feel honored to continue to do so.