One of the problems that the DoD tried to address during the Cold War was that of ‘fratricide’, or the tendency of a detonating warhead to prevent later arriving warheads from exploding properly. This suggests that any Syop would have to launch ballistic missiles & cruise missiles in waves and have the targets spaced out during each wave so that 1 nuke wouldn’t influence another.
I would think that a dropped Trident detonating would probably not cause a chain of nuclear detonations. Of course 1 would be bad enough.
I wonder what kind of warheads the Brits are sticking on their Tridents? Could it be a US-design?
SYOP = SIOP