I have to say that I'm not seeing a ton of evidence that the US really wants to go forward with the JCPOA. The "adhere to the old agreement and then we'll come to the table" position seems designed to be unacceptable to Iran.
It's designed to partially neutralize partisan attacks from the right. I expect diplomatic discussions are far more substantive and nuanced, while the executives figure out how to manage the optics of an agreement.
Well, if that’s what they’re thinking, surely they have to take into account that Iran has its own hawks who oppose a new deal in the first place and will surely seize on a narrative of national humiliation.