I disagree, this is intensely political. Corbyn uses his CND credentials as a plank of his manifesto. When a serving Officer criticises it and sheds doubt on his maturity he is entering the political arena by commenting on Corbyn's political stance. Corbyn does not want a nuclear deterrent and does not subscribe to MAD. Should he ever be elected (god forbid) and his policies prevail, the military will have to adapt to a new stance, as the South African military have when they unilaterally nuclear - disarmed.
There is a parallel with chemical and biological weapons, our politicians have decided not to deploy them. Not so other countries. The asymmetry exists, we live with it.
Establishing the logic of a nuclear deterrent is a military topic. Adopting and deploying it are political.