My guess is we will have JCPOA 2.0.
It may be straight to a deal without any war or just a limited strike, retaliation from iran. Then a cease fire and finally slowly towards a deal.
Basically I don't think we will have a massive war, so far trump hasn't shown this kind of behaviour, in 2017-2018 he done similar build up relative for north Korea and threat levels were high but nothing happened. He is after optics, short victories, and backdoor deals.
Also Iran has too much deterrence, Israel hasn't stocked up on interceptors, Gerald ford carrier is in need of maintenance and low crew morale. Oil prices could shoot up and trigger financial crisis and internal protests.
On the other hand for trump to move all this force and then back off without signing a deal, even if he does a limited strike doesn't make sense, in other words this build up must be for negotiating leverage.
So after deal is signed, Iran starts relying on imports again, internal industry suffers a bit, then a few years later, next president will probably withdraw again from the deal, be it trumps third term, Vance or anyone else.
Essentially goal being to keep Iran always in limbo, and so that it can't attain true self sufficiency.
Somewhere in between they will probably start a civil war in Iraq, sending in Sunni extremists, and mercanaries from syria to weaken the PMF and further isolate Iran.
And over time they will degrade Hezbollah through attrition.
If they cant change or balkanise the country, then just always keep it weak through soft power.