I will move on to the next point, Mr Deputy Speaker.
My right hon. Friend the Defence Secretary is fond of describing Trident as an insurance policy, but I counsel him to use that phrase sparingly, because the maintenance of our nuclear deterrent is so much more than just an insurance policy. It is not a premium. That description “de-emphasises” the way in which the deterrent is continuously used, shaping our global security environment, and expressing the character of our country and our national will and resolve. It does not sufficiently emphasise its deterrent quality, which is not to deter terrorism or much lower forms of combat.
The invention of nuclear weapons has undoubtedly ended large-scale state-on-state warfare, and I would even be so bold as to suggest that were we to disinvent them, we would be inviting the resumption of such warfare. I am not sure that human nature miraculously changed after 1945, but something in the global strategic environment certainly did, and we no longer see that large-scale state-on-state warfare.
Members of the Scottish National party have made much of the cost of Trident today, but let me ask them this question: how cheap would it need to be before they regarded it as good value for money? I do not think that that is an argument with which they are prepared to engage. They are against nuclear weapons whatever the cost, and they are perfectly sincere about that, so I invite them to stop bellyaching about the cost, because it is an irrelevant part of their argument.