[jcranmer]

Nuclear weapons have long (since the late 50s at least) had a peculiar calculus that amounts to the prisoner's dilemma: whether or not your adversary has nuclear weapons, there is more value for you to have them, so you end up in a situation where everyone feels justified to have them, even if it's the worst situation overall.

This has created a few paradoxical situations. One of them is that their strategic value lies primarily not in their use (which will not achieve any result) but rather the threat of use, which may be sufficient to dissuade leaders from committing to a war (arguably, this happened during the Cuban Missile Crisis--both Kennedy and Khrushchev blanched at the prospect of starting a nuclear war). Another interesting side effect is that this means that the development of counter technologies produces staunch opposition: nuclear war has to be seen as unwinnable for its deterrent value to be effective.

Part of the motivation for nuclear weapons as a strategic (rather than deterrent) option comes from the lineage of people who see strategic bombing as an fast, cheap, easy way to win a war. For a century now, adherents have predicted that once you started bombing a few cities indiscriminately, you'd easily win a war. And people continue to argue this despite the rather thin evidence for this proposition, and mountains of evidence in opposition.