There was no corner of the known world where some interest was not alleged to be in danger or under actual attack. If the interests were not Roman, they were those of Rome's allies; and if Rome had no allies, then allies would be invented. When it was utterly impossible to contrive such an interest—why, then it was the national honor that had been insulted. The fight was always invested with an aura of legality. Rome was always being attacked by evil-minded neighbors, always fighting for a breathing space. The whole world was pervaded by a host of enemies, and it was manifestly Rome's duty to guard against their indubitably aggressive designs. They were enemies who only waited to fall on the Roman people.
Joseph Alois Schumpeter, Imperialism and Social Classes: Two Essays by Joseph Schumpeter
government, imperialism, war