The Nuclear War Plan for Iran

Well in a way they would be but the US wants to be the one to actually field the weapons. The zionists have been saying they might resort to using their nukes and Trump and the US given the strategic situation are saying, "no, if they're used, we'll use them to assert our power and dominance and deterrence and enhance our credibility as an empire that can still fuck you up if you don't obey us". Plus the US doing it vs the zionist entity means less blow-back for the zionist entity directly. If the zionists do it, with the current climate against them through much of the world a BDS movement might build to a fever-pitch amid calls to completely isolate the outlaw state which would be a headache at least for the US requiring them to pour more resources in. But if the US does it, well the US is vital to world trade and though they're pissing people off with tariffs presently it's not practical to attempt to strangle them from a consumer point of view via buying choices and pressure campaigns given their size, reach, financial, economic, cultural, etc power.

And best of all with the US they have Trump in power who has been sold as an aberration. They can simply push him out or he'll die and then they paint his actions as too far, as being those of a dictator and that the US has changed(tm) and was like that then but has learned and is now better and a perfect angel.

Mostly the US fears its vassals nuclearizing and gaining independence from them that way. Very few strategic enemy countries to the US don't already have nuclear weapons already so the risk of proliferation is not really seen as a problem in using nukes. Vietnam still isn't likely to pursue a nuclear weapons program but even if they were they're important enough to China that the US couldn't invade without Chinese retaliation anyways. Other than that who is there? The AES alliance in Africa might have the raw uranium to make nuclear weapons possible but they lack the industry, the science, the knowledge, and the base to put them together and build ICBMs anywhere near fast enough to be able to create a credible deterrent (though they are close enough to Europe they could get by with shorter range missiles able to hit 2500miles away in say Berlin or Paris and use that to threaten the US into backing off, still even that would take a lot of work).

Importantly using nuclear weapons in defense of a vassal would the US may think re-assure other vassals like occupied Korea who have been murmuring about acquiring their own nukes, would re-assure them not to try and do that but that the US will use nukes in their favor if the time comes (hint: it won't as long as the DPRK can hit numerous cities in the US mainland in retaliation which it should be able to soon). So it would be a credibility building maneuver after Ukraine's humiliation.