Being Devils Advocate:
The UK is perhaps the worlds leading light in Chemical and Biological warfare. Easily delivered by both short and long range manned and remote platforms.
Comrade Corbyn suggested yesterday that the Trident replacement could cost in excess of £200billion. I dont think we need the expense of Trident although I do believe that Battlefield tactical nuclear weapons and depth charges have their place.
We have seen that the globe is an unpredicable place and my 'what if' is that a need for nuclear reponse is hypothetically in the northern hemisphere whilst the 'Duty boat' is parked off Buenos Aires second guessing a perceived threat. I will say though; WTF do most of the residents of the Commons know about military matters.
In summ: The argument against Trident could have been served with something a little more substantial then it was; the caveat being that it was not UK Nuclear Response being discussed, rather one specific delivery mechanism.