I didn't comment as to when the original implementation for the Vanguard subs was decided; I pointed out that it's common knowledge that there is in fact typically only one sub active at a time. Agreed, then. I also understand the reasons for shifting the "delivery platform" (such a nice placid choice of words for world-ending hardware). That wasn't part of my argument either. It still remains that there is only one platform (and literally one active at a time) which has been losing support and personnel as the decades have rumbled on. Increasingly, we can barely afford to support the absolute minimum system that we now have.
The dropping of Nimrod shows the lack of both commitment and funds for maintaining an ideal level of defence and surveillance for the subs themselves and other conventional vessels. 'Having them' it seems, is more important than providing a robust level of air support to the rest of the force - it makes the 'multi-faceted' argument fall over just little.
And while I understand the basics of the 'political will' debate, it ultimately reads as posturing without looking at the whole picture. Trident exists at the expense of a strong conventional armed force, which can equally be considered a massive weakening of UK defence. Part of the reason we still think of a nuclear arsenal as necessary, is that our own foreign policy leaves a huge amount to be desired. We still don't even know how to deal with 60-year-old nuclear waste (much of it from the original UK weapons development) in rotting/leaking storage units at Sellafield, which remains one of the most most dangerous industrial sites in Europe. In other words, the dangers faced are clearly not just external threats.