This has been discussed on PPRuNe before, as the SEARCH function will reveal. I must say that personally I am not totally convinced that we need a deterrent on the scale of the V Force/Polaris/Trident, or anyway near it.
A few links..........
1. See this from Richard Beedall:
VANGAURD(Replacement)
In order to keep costs down, an all-new submarine design has become considered unlikely for a Vanguard-class replacement and current thinking probably assumes an evolution of the Astute design - indeed BAE Systems Submarines has already examined two variants fitted with an extra hull section. The first includes the fitting external to the pressure hull of sixteen Mark 36 Vertical Launch System tubes for missiles such as Tomahawk, and the second includes four Trident II size (86 inch diameter, 36-feet usable length) missile tubes, installed aft of the fin. The later approach is preferred as the large tubes are extremely versatile, alternative to Trident II SLBM’s they could potentially carry a next generation ballistic missile, a multiple all-up round canister accommodating seven Tomahawk cruise missiles per tube, equipment and swimmer vehicles for special forces, Unmanned Underwater Vehicle’s (UUV’s), deployable decoys and sensors, and even encapsulated Unmanned Air Vehicle’s (UAV’s). While a re-role will not be trivial, the new submarines would certainly be far more flexible than the current SSBN/SSN divide permits.
2. From BASCINT:
Trident: Do we really need to make the decision now?
3. From the UK Defence Forum:
Thinking the Unthinkable - Modifying the Vanguard class nuclear capacity
4. From the same group:
Thinking the Unthinkable - New roles for Vanguard?
Note both of these papers were written in 1997.
BHR are you really saying you think nuclear weapons did not play a part in restraining the hot heads in both Moscow and Washington?