Armies and states throughout history have sought to provide security by constructing fixed fortifications like fortresses, citadels, and walls. These projects inevitably end as dismal failures. Not only do they not provide security, but they do something even worse: they provide an illusion of security that encourages a defender to be overconfident and careless. And when this happens, disaster is only a matter of time. Walls and forts do not provide security; at most they can help channel avenues of approach for advancing enemies. For states are not protected by fortresses, but by the valor of their citizens. When the latter is lacking, the former are of no use.