time delay. would have been silly to build a system that triggers instantly, seeing as a geomagnetic storm or whatever would initiate nuclear annihilation
Sure, but how do you balance the time between that needed for recovery from a Carington-level event, and leaving it too long such that the adversary has taken out your silos and subs?
I would speculate it's not a one part scheme. First, a network of international spies would surface, then they could do whatever, even use the enemy nuclear weapons against them
> The Carrington Event was the most intense geomagnetic storm in recorded history, peaking from 1 to 2 September 1859 during solar cycle 10. It created strong auroral displays that were reported globally and caused sparking and even fires in multiple telegraph stations.
The whole point of having subs is that they are meant to be stealthy and survive the initial strike. If you took them out it's game over and the dead hand system is useless.