Of course it is recent accounting innovation to bring Trident into the core defence budget. Previous nuclear programmes were kept separate simply because while their strategic utility was not questioned, neither was their lack of tactical utility.

The problem with Hitchen's analysis is that he is basing the utility of Trident on the world now, not the world in 20 years time. Having started my erstwhile military career facing 3rd Shock Army on the Inner German Border and then less than 15 years later finding myself with German Fallschirmjaeger on the Tajikistan border operating alongside Uzbeks against the Taleban, I am not sure I would want to make that prediction.