LESSONS FROM THE FALL OF ROME: The Stages Of Grief At The Frontier. “First, there is the gradual recognition that imperial forces were not what they used to be. The tangible presence of the empire was disappearing, and the towns were losing their main security providers. ‘So long as the Roman dominion lasted, soldiers were maintained in many towns at the public expense to guard the boundary wall. When this custom ceased, the squadrons of soldiers and the boundary wall were blotted out together.’ But the gradual withdrawal of Roman troops did not seem to have had a shocking impact on the locals, who perhaps did not notice immediately that their security required the presence of armed men. Indeed, few consider how security and deterrence are maintained while peace reigns.”

Plus: “Second, after the reassuring presence of imperial might has vanished, the next stage does not include calls for defense or balancing or stronger walls. No. It is the stage of disbelief and self-delusion. As Roman power waned, the locals comforted themselves with the delusion that the threats did not exist or, if they did, that the menace was not great. Perhaps the enemies would seek other targets. Perhaps the walls would suffice. Perhaps the barbarians liked peace and commerce as much as they did. Perhaps they would just go away. Perhaps they would peacefully blend in. The list of possible justifications for this delusion is as long as it is wrong.”