No, you're still missing the point. I mean a massive US conventional attack. So far in the current conflict the US has used only a fraction of its capability, and only targeted military and government facilities. In a scenario where Iran claimed to have nuclear weapons then the US would hit much harder and aim to cause so much infrastructure damage and civilian casualties that Iran would be unable to build much of anything more complex than short-range rockets.
This is an absurd fantasy. Most of Iran's military capability is deep inside mountains. If the US & Israel wants to adopt a strategy of Vietnam-style carpet bombing to devastate the entire country, not only will they be making themselves pariahs (which they're already on the way to doing) but they will be incentivizing Iran to hit Israel with dirty bombs, which will collapse the Israeli economy in short order.
A massive conventional attack against a nuclear power is historically not a thing. That's the whole point of a nuclear deterrent. No one is attacking Russia or North Korea under pretenses of humanitarian interventions. A massive conventional attack that would tear Iran apart would be a sufficient reason to initiate nuclear armageddon between Israel and Iran, as it would be a doomsday event for Iran either way; might as well go down swinging. Again, that's the whole point of a nuclear deterrent. It's what Israel's Samson option is, even though none of their enemies ever possessed nuclear weapons.
No, you're still missing the point. The massive conventional attack will tear Iran apart before they construct enough nuclear weapons to present a credible deterrent.
No, you're still missing your own arguments, based on which this discussion thread has been based. Citing your exact words:
> Furthermore, if Iran declared that it did possess working nuclear weapons that wouldn't be a deterrent: it would trigger an immediate and massive preemptive attack by the USA and Israel.
I've been discussing this under the assumption from your own words that "it did possess working nuclear weapons" ('it' being Iran). If you are now changing this to a massive escalation before they even get it, then that is out of scope for this discussion. I would argue they are already doing that to the extent that they can, as they have to tread carefully since Iran can also destroy all key infrastructure in Israel as well.
Having a working nuclear weapon is not the same thing as having a viable vehicle to deliver the nuclear weapon somewhere useful, unless we're talking like, suitcase nukes or whatever. It's hard for me to estimate what the timeline would be to retrofit their existing ballistic missile platform to be suitable, but it's not a super easy task - timeline in peace times would be years, most likely. War likely accelerates it... unless the key people you need for the program, the supplies, testing resources, etc., are victims of the war.
'Working nuclear weapons' is a really broad scale so it's tough to extrapolate without knowing if it means "they can send a person with a low yield weapon somewhere and blow it up vs. "they can launch a high yield weapon on a ballistic missile anywhere within 2000km"
