The Pentagon has completed initial draft plans for several emerging low-yield sea-launched nuclear weapons intended to deter potential attackers and add new precision strike options to those currently possible with the existing arsenal.

While final requirements for both a low-yield sea-launched nuclear cruise missile and long-range sub-launched low-yield warhead are still in development, Pentagon officials tell Warrior Maven the process has taken several substantial new steps forward.
http://www.foxnews.com/tech/2018/06/...ar-weapon.html