A week on from my declaration that I’m giving up politics, my mind has settled a little more, and I realise more fully what I meant by that. I remain interested — fascinated, even — by fundamentals: what you might call political philosophy. What I have no time for or patience with is current affairs: the specific set of events and personalities that are in the news right now. That stuff is both ephemeral and monumentally frustrating, so best ignored. But the core issues continue to exercise me.
So when should we use a nuclear deterrent?
I assume out of the gate that we are all civilised, and would never initiate a first strike.
What you need is for potential aggressors to genuinely believe that you would use your deterrent in retaliation — because if they believe you would retaliate, they will be less likely to attack. (That is why Jeremy Corbyn’s insistence that he would never use Trident is poor tactics, whatever you think of the morality behind it.)
On the other hand, you don’t ever want to actually retaliate: because us and Russia both wiped out is worse than us wiped out and Russia not.
So what you really need is a leader who, while planning never to use our weapons, can convince the world that he or she will. In other words you need a consummate liar.
(All of this is of course assuming that you’ve already got the deterrent, or committed to building it. In light of yesterday’s Trident vote, I am taking that as a given.)