The whole point of having nuclear weapons is that they only are useful if you never get to use them (or, if you really want to be cynical, at least not use them against another nuclear power). The moment you pull the trigger, it's game over and everybody loses.
This is not some naive pacifist nonsense, it's sheer rationality.
And yet paradoxically that means they are only useful if one's potential opponents believe you will use them in certain circumstances. If we're simply not ever going to use them, then we might as well get rid of them and save the expense of building them. Abandoning nuclear deterrence means either having a credible conventional deterrence or being will to be gobbled up by the bear, if there is a bear.
Your trigger metaphor applies just as well to conventional war. Do you really think either Ukraine or Russia has gained anything from their current tussle?
Well yeah, it's pretty clear Putin feels like he's gained a lot out of it. And what are you saying, that the US should threaten to nuke Russia if it doesn't back down?
