via dollarsanddatda:

Always/Never

The problem with designing a nuclear bomb is the inevitable tradeoff between reliability and safety. Schlosser explains in Command and Control:

A safety mechanism that made a bomb less likely to explode during an accident could also, during wartime, render it more likely to be a dud. The contradiction between these two design goals was succinctly expressed by the words “always/never.” Ideally, a nuclear weapon would always detonate when it was supposed to — and never detonate when it wasn’t supposed to.

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