On balance I am not in favour of nuclear weapons. I never have been (the first demo I went on was a CND one). I was always of the opinion that the nuclear arms race was an offensive campaign to wreck the Soviet economy (and it worked - and perhaps that was for the best) rather than anything to do with defence against aggression, and I think they have become less relevant than they were.
Be all that as it may - and I accept that there are forceful arguments against that position - there has been much flak given to Corbyn for his evident refusal to be willing to launch a nuclear first strike. A BBC Question Time audience seemed to be baying for someone ready to fire ballistic missiles at all and sundry. By contrast, Theresa May and Michael Fallon have said they would launch a first strike. This is apparently 'strong and stable' government to keep you safe. It is of course nonsense and it actually shows how utterly irrelevant nuclear weapons have become.
Because the whole logic of nuclear deterrence relies upon a rhetoric of not being willing to launch a first strike. Deterrence relies upon willingness to retaliate. (and that's where the tricky arguments actually start). In other words 'if you shoot first, we will shoot back and everyone dies.' That is the essence of 'mutually assured destruction' which - according to some people - prevented the cold war from becoming hot (unless you were unfortunate enough to live in, say, Korea, or Vietnam, or parts of Africa, the Middle East or Central America, of course). The rhetoric relied upon a constant moral deterrence from using weapons, a moral weight placed upon the shoulders of those who might otherwise be willing to shoot first and start the war, a moral weight that said 'even if you win you lose'. There was a very good and illustrative segment in 'Yes Prime Minister' in which (fictional PM) Jim Hacker was asked in various scenarios when he would launch the nuclear weapons in response to a non-nuclear Soviet offensive and was unable to answer positively at any point.
Think about it even for a moment. If Cold War rhetoric had been a 'gunslinger's argument', about which side could, and was most prepared to, 'shoot first' the human race would have become radioactive toast by 1963 at least, or in the 1980s.
The fact that May and Fallon can broadcast a willingness to launch a first strike and deride those who maintain the moral reluctance to do so as being 'weak' only shows that nuclear weapons (and the geopolitical rhetorical and military value of nuclear weapons) have become quite irrelevant. They have become a simple, meaningless football in macho internal political contests. Corbyn may be against nuclear weapons but in fact his stance is the one that is most in line with the serious 'defensive' argument for their retention.