(off-topic, but I find it fascinating) The UK system sounds back-asswards, but it strikes me as a surprisingly sane set of checks. Man vs Machine has always b

(off-topic, but I find it fascinating) The UK system sounds back-asswards, but it strikes me as a surprisingly sane set of checks. Man vs Machine has always been a royal navy doctrine. The US teaches nuclear engineers how to drive a boat. The UK teaches sailors how to run a nuke. Similarly, if the boat has to maintain independent firing capability (the whole point of the deterrent being in submarines is to avoid command&control decapitation), then any access control is a formality. If control ultimately falls to the crew, then don't pretend it doesn't - focus on the men. Radio 4 sounds anachronistic, but it's a UK-based, govt-controlled transmitter, independent from military systems, which broadcasts every second of the day during routine operation - and because it's still cranked out on longwave (198?khz), can be heard across our waters & much of the north atlantic (the stomping grounds of our deterrent). While civilian maritime broadcasts would sound like a more sensible failsafe, most of them are either broadcast or controlled from Northwood, so they're not independent of military systems, and are routinely silent between scheduled broadcasts. What I do find interesting is the actual point of checking for civilian broadcasts - given the loss or failure of command&control communications, the result isn't a railroad to Armageddon - they're expected to implement some common sense. Compare this to the scenes in Crimson Tide, where Gene Hackman prefers blind obedience to the Protocol .. And "hand-written" is a red-herring. The actual detail here is that only the PM ever knows what went in that letter once it's sealed. They don't have to be hand-written, and probably aren't anymore - but traditionally this was a side effect of not dictating to a secretary/typist.