>What you’re saying is that there was a deliberate mechanism by which a single man could turn both keys and trigger a launch? That’s WarGames-level horrifying.

Isn't the opposite mostly a security theater? As if a single person couldn't do it with some ingenuity anyway even on mechanisms that need two persons?

For starters, they could always point a gun to another person to make them turn the other key...

If you point a gun at someone they don't necessarily do as you wish. In military situations the personnel are trained (some might say brainwashed) to sacrifice themselves; which should be relatively easy when the alternative is that all your family die from radiation poisoning (or obliteration if they're lucky).

Arguably in some regimes chain-of-command is a greater incentive than a gun as retaliation against families (for "treason"/cowardice) seems reasonably common.

When I read this, I was reminded of the tricks some train operators have used to bypass the "dead man's switch," sometimes with horrifying results.