One of the problems (for me) in deciding whether I think we should replace the Trident system with a similar system is that I have no idea what the real cost of this would be. Large sums of money are often quoted but do they (for example) recognise the income tax paid by all the individuals involved in this programme in whatever capacity.
Another problem is that if we binned it would the money actually go to anything more worthwhile?
What about the industrial and scientific base associated with the total Trident system - does it have no other useful spin-offs? Would there be unexpected consequences to binning all that?
I SUSPECT that the above points might actually be quite important so in the absence of knowing the first thing about any of this my gut feel would be to keep it.