Anyone who has ever studied the history of American diplomacy, especially military diplomacy, knows that you might start in a war with certain things… - George F. Kennan

War has a momentum of its own and it carries you away from all thoughtful intentions when you get into it. You know where you begin. You never know where you are going to end

A foreign policy aimed at the achievement of total security is the one thing I can think of that is entirely capable of bringing this country to a point where it will have no security at all. And a ruthless, reckless insistence on attempting to stamp out everything that could conceivably constitute a reflection of improper foreign influence in our national life, regardless of the actual damage it is doing to the cost of eliminating it, in terms of other American values, is the one thing I can think of that should reduce us all to a point where the very independence we are seeking to defend would be meaningless, for we would be doing things to ourselves as vicious and tyrannical as any that might be brought to us from outside.
This sort of extremism seems to me to hold particular danger for a democracy, because it creates a curious area between what is held to be possible and what is really possible — an area within which government can always be plausibly shown to have been most dangerously delinquent in the performance of its tasks. And this area, where government is always deficient, provides the ideal field of opportunity for every sort of demagoguery and mischief-making. It constitutes a terrible breach in the dike of our national morale, through which forces of doubt and suspicion never cease to find entry. The heart of our problem, here, lies in our assessment of the relative importance of the various dangers among which we move; and until many of our people can be brought to understand that what we have to do is not to secure a total absence of danger but to balance peril against peril and to find the tolerable degree of each, we shall not wholly emerge from these confusions.

If humiliation and rejection are to be the rewards of faithful and effective service in this field, what are those of us to conclude who have also served prominently in this line of work but upon whom this badge has not yet been conferred? We cannot deceive ourselves into believing that it was merit, rather than chance, that spared some of us the necessity of working in areas of activity that have now become controversial, of recording opinions people now find disagreeable, of aiding in the implementation of policies now under question. … In no field of endeavor is it easier than in the field of foreign affairs to be honestly wrong; in no field is it harder for contemporaries to be certain they can distinguish between wisdom and folly; in no field would it be less practicable to try to insist on infallibility as a mark of fitness for office.

Not only the studying and writing of history but also the honoring of it both represent affirmations of a certain defiant faith — a desperate, unreasoning faith, if you will — but faith nevertheless in the endurance of this threatened world — faith in the total essentiality of historical continuity.