Fritz Stern in Lapham’s Quarterly:
The great French historian and resistance martyr, Marc Bloch, is supposed to have said that history was like a knife: You can cut bread with it, but you could also kill. This is even more true of historical derivatives like analogies; they can provide either illumination or poisonous polemic. The first requirement for an acceptable historical analogy is plausibility; the two situations compared must have striking similarities, and the image of the historic antecedent must be as clearly understood as possible. This becomes an unlikely presupposition when the analogy is proposed by partisans working in an age of stunning historical ignorance. Nowadays, politicians and partisans use analogies instead of arguments, convenient shorthand for their defenses of dubious policies.
It was beneficial that President Kennedy was conscious of historical analogies. During the Cuban Missile Crisis of 1962, he remembered how easily nations had slipped into World War I in 1914, and how important it was to give an adversary a chance to back down while saving face.