Here's the thing about submarines you may not realize: they are the trump card when it comes to nuclear warfare and keeping MAD in place. If one country "struck first" and tried to wipe out our nuclear silos, nuclear armed subs would retaliate. Given the surface are of the world covered by water, there are quite a few hiding places too. What happens to MAD after we have a reliable way to detect subs? :/ Don't really…
They aren't the sole trump card, that role is also played by manned bombers that can launch on warning from the middle of the without committing to bomb that targets, without even having the ability to arm their warheads ( https://en.wikipedia.org/wiki/Permissive_Action_Link ); SLBMs are trump cards against undetectable attacks, or at least ones that can be detected in time, see for example https://en.wikipedia.org/w…
https://en.wikipedia.org/wiki/Multiple_independently_targeta...