We have to try to detect submarines, because we cannot afford to let the Russians find a technique that we do not know, and because we have to learn all we can about detection to make our submarines less detectable; but like a person who has entered into an agreement with a partner that he cannot trust, we may search like the devil for a loophole, knowing that our partner is searching just as hard, while hoping that no loophole is to found.

Thomas C. Schelling, The Strategy of Conflict, loc. 543