you've heard that british navy does not have enough active attack subs to guarantee a safe (i.e. untracked) exit of an ssbn and recently had to ask americans to ensure that no russki was shadowing them? this isn't a dunk on bongland btw (as much as i hate your country, no offense), but a cry for help with just how bad the naval situation has become.   no, having a nuclear ssbn at sea is much cheaper and great insurance against a decapitation strike. russia and usa do the same things. i am sure china does as well.
United States