Earlier quoted context omitted.
> What target could the Iranians hit you believe would provoke a nuclear response? Anything existential. (Tehran doesn’t currently have that capability.)
I don't know what you classify as existential. But unfortunately it is drop-dead easy to make a fission bomb and even easier to make (multiple) dirty bombs. Iran has the pieces to do these things many times over. Hell, by now they could have deployed dirty bombs abroad in multiple locations and we'd never know. The only reason the USA doesn't flatten Iran with nukes is that the USA fears Russia will view it as an "al…
In addition I would hope that even in the morally bankrupt state USA is in today, murdering 92 million people would cause some political problems (but this might be naive of me).