The W-88 warhead has a yield up to 475 kt.
There can me up to 8 warheads on each missle.
One US SSBN with 24 Missles is much more than needed to eliminate the NK problem.
I'd assume one or more is near enough to NK at all times.
The W-80 warhead on cruise missles arming the attack subs have a yield up to 150 kt.
Since the Kitty Hawk is now on patrol near NK,
there are a couple of the attack subs already there too, as part of her battle group.
Murphy is alive and well this morning.