The problem with deterrence - apparently sometimes forgotten by our former presidents - is that it is not static, but a creature of the moment, captive to impression, and nursed on action, not talk. It must be maintained hourly and can erode or be lost with a single act of failed nerve, despite all the braggadocio of threatened measures. And, once gone, the remedies needed for its restoration are always more expensive, deadly - and controversial - than would have been its simple maintenance.
While I complain of being able to glimpse no more than the shadow of the past, I may be insensitive to reality as it is taking shape at this very moment, since I have not reached the stage of development at which I would be capable of perceiving it. A few hundred years hence, in this same place, another traveller, as despairing as myself, will mourn the disappearance of what I might have seen, but failed to see.