Not true, at least in the US and Russia. More than one person in the chain of command needs to commit to an all-out nuclear attack. It is perfectly plausible that someone along the chain would not follow such order.
Ok, maybe one was a bit of an exaggeration.
I should have said "All it takes is one deranged individual and a handful of his his hand picked sycophants."
In some firing squads there's only one bullet and the rest are blanks -- though if you've been in one, some say you can tell the difference between the bullet and the blank. The idea is to give a plausible deniability to those that follow the order: "It wasn't my gun that had the bullet."
If the method for delivering the nuclear order is routine and 99.99% benign (except for the 0.01% where it's not) and the order is checked only by machines, then no one would know except for the person that made it.
Further, to enforce compliance with routine behavior, one just needs to threaten the family of the subordinates. Or better yet, occasionally take one of your subordinates and make an example out of them, once every two years say. Send them and their family to labor camps never to be seen again.
Not true, at least in the US and Russia. More than one person in the chain of command needs to commit to an all-out nuclear attack. It is perfectly plausible that someone along the chain would not follow such order.
Here's a twitter thread (in German) explaining how this supposedly works in Russia: https://twitter.com/SwenRoschlau/status/1498575623941505026