There was a TV programme* a few months ago which played out a scenario with real politicians and senior (retired) military people. Russia provokes unrest and then invades a Baltic state (just like Ukraine), which as a NATO country we are committed to defend. Can't remember the exactly the way it played out, but it became certain that the Russians were going to nuke a variety of European cities (Berlin, Copenhagen, Warsaw I think). Britain was carried along on the US coattails the whole way. The politicians were, not unanimously, in favour of using our weapons. The most senior military man was not in favour, on the grounds that the civilian deaths involved were unjustifiable and that the US would use theirs anyway, our arsenal is irrelevant. All seemed terrifyingly plausible to me. This was before Trump, who as an isolationist might well just say 'nothing to do with us'.
I posted on this earlier on this thread, but I don't think anyone was interested in the debate (fair enough). While I don't have a problem with technology that exists, cannot be uninvented, and is, of itself, nothing to do with morality, I can be persuaded either way on whether the UK needs its own nukes. The only circumstance I can imagine supporting their use is a limited nuclear strike to prevent a big nuclear war. Which of course would be a massive gamble that it would work, and I can't really see the UK leading this approach, more likely to support the US so the moral blame is shared (the use of the weapons, rather than the weapons themselves, is where morality comes in). With a 'no first use policy' (I think only India and North Korea have this policy) we really don't need these weapons, so it is pointless us keeping them if Corbyn is PM.
So for me a practical decision. What I am 100% convinced of is that the existence of these weapons, which in itself is a horrible risk, has saved millions of lives in preventing conventional wars between major powers. How quickly would the Cold War have descended into fighting without this terrible deterrent? Europe would have been a wasteland in the fifties.
Just heard Irritable Bowel Smith 'debating' Ed Millillilliband on the wireless. The ultimate tallest dwarf contest, Ed wins by a short head.
* tracked it down, called 'World War Three:Inside the War Room', was on BBC4. Few clips but unfortunately not the whole thing on YouTube.