|SSBNs have long been regarded as the most secure leg of the nuclear triad providing a nuclear deterrent. As a result, some countries, and I am mostly thinking of Britain, have switched to a nuclear deterrent based solely on SSBNs.
Recently, though, news of new technologies in submarine detection have begun surfacing. Some, such those described in the recent SP article, rely merely on major improvements in passive sonar technology, but others introduce wholly new forms of detection, including those based on shining 'laser' beams into the sea and detecting submarines on that basis (I am guessing through relfection patterns, but I am no expert). This is not to say that SSBNs will suddenly be easily foundable and destructible. I have, however, started to believe SSBNs or other submarine-based forms of nuclear deterrence relying in the undetectibility/stealth of submarines will become more vulnerable, as multipronged approaches to submarine detection begin to proliferate in the years to come.
So, in the light of this, how would you ensure that the nuclear deterrents (of whichever country) remain secure? I guess nothing beats diversification and having a full nuclear triad with multiple types of approaches withing each leg of the triad (e.g. both hardened silo and mobile ICBMs for the land leg). This ensures that even if new technologies increase the vulnerability of one part of the deterrent the other parts compensate for it, but it is a very expensive solution. What would your suggestions be to deal with the issue?