More like half active, a quarter in port or in light maintenance, a quarter in deep maintenance. Realistically, two always on station from each fleet, sometimes four. Enough to maintain second strike deterrence even with enemy attack subs to contend with.
It also important to note that once an SSBN launches, there will likely be return fire from either land or sea based ballistic missiles that will boil the ocean for 50nm, incoming in 30-60 minutes. So tactically it is hard to launch just one nuke... It's full commitment or nothing. Just another cheery aspect of escalation dynamics.
It also important to note that once an SSBN launches, there will likely be return fire from either land or sea based ballistic missiles that will boil the ocean for 50nm, incoming in 30-60 minutes. So tactically it is hard to launch just one nuke... It's full commitment or nothing. Just another cheery aspect of escalation dynamics.