It's uranium, you can't simply hide it in the matter of days. Not to mention 24/7 video surveillance, satellite images, and that IAEA released quarterly reports and every one of them until over a year after US withdrew from the agreement said the same: Iran complied. Hell, even a year after Iran let IAEA know that they're gonna exceed their limits. Here's the entire timeline for those interested: https://www.armscontrol.org/factsheets/Timeline-of-Nuclear-D...

Nothing like the situation was with North Korea, where North Korea was uncooperative with the IAEA, mostly disagreeing on which parts of the plants IAEA can access. Not to mention IAEA had 20 years in between to improve their methods.

US absolutely shot themselves in the foot by withdrawing from the deal no matter how you look at it.

>It's uranium, you can't simply hide it in the matter of days.

The problem here is that Iran was allowed to not tell all on previous existing program. Lets pretend they cheat and IAEA finds out traces of Uranium. What happens when they argue that the Uranium signature is pre-2015 and not from a new installation? There's not enough time passed to prove either way.

> US absolutely shot themselves in the foot by withdrawing from the deal no matter how you look at it.

US had to look for improvements, even if Clinton had been elected, since the agreement was designed to be temporary. The tactics involved are a different matter. I guess Trump could have been more devious and unofficially sanction Iran while officially staying part of the deal. Would that have been better? Hmm.. difficult to say.

>>What happens when they argue that the Uranium signature is pre-2015 and not from a new installation?

Is this even possible? Doesn't the half-life of the enriched uranium reveal when it was enriched?

>>The tactics involved are a different matter. I guess Trump could have been more devious and unofficially sanction Iran while officially staying part of the deal. Would that have been better? Hmm.. difficult to say.

The US could have stayed party to the nuclear deal and coordinated any new negotiations with its European allies, and that would have been substantially better than reneging on an important nuclear arms control deal.

>Is this even possible? Doesn't the half-life of the enriched uranium reveal when it was enriched?

I am not an expert, but I believe Carbon dating is based on similar principles. Yet archeologists always give +-100 years variation in their estimates. Could IAEA really get to +-10 years or better? None of this would matter normally, except for the particular structure of the deal.

>The US could have stayed party to the nuclear deal and coordinated any new negotiations with its European allies

Support from the EU isn't the real question. We see the US can enforce unilaterally. Nor would Iran act differently if the EU had fully joined the pressure, or if the EU would also have torn up the deal. The question was whether to fix from inside or tear it up. Either way it would have to involve pressure.

Detection of any enriched uranium at a site, combined with evidence of recent earth work, would be a pretty clear smoking gun, so I don't think that would be a viable way to avoid being held accountable for unauthorized nuclear enrichment.

>>Nor would Iran act differently if the EU had fully joined the pressure, or if the EU would also have torn up the deal.

Reneging on a deal undermines the credibility of the diplomatic process and ratchets up tensions which increases the chance of a military conflict. Having a united front is good both for cross-Atlantic ties and the chances of resolving the dispute peacefully.

>Detection of any enriched uranium at a site, combined with evidence of recent earth work, would be a pretty clear smoking gun,

The UN/IAEA process requires unanimity among the major powers. Since Iran has been left with an semi-believable out, there's enough diplomatic cover to allow Russia/China to cover for it there (see Syrian chemical weapons for comparison). For once such a position would be understandable: If seeing enriched Uranium could eventually lead to war, and there's a way to rationalize it, how much of a smoking gun would it be? Allowing that rationalization was an error in the deal.

> Having a united front is good both for cross-Atlantic ties and the chances of resolving the dispute peacefully.

The structure of the deal made some form of renegotiation inevitable (since the main restrictions were temporary). The question is how to do it.

>>The UN/IAEA process requires unanimity among the major powers.

I think your assessment of the outcome of said smoking gun is unrealistic. The scandal described would have massive political repercussions that would go far beyond any letter of the deal.

>>The structure of the deal made some form of renegotiation inevitable (since the main restrictions were temporary).

Why would it inevitably need to be renegotiated?

>>The question is how to do it.

By honoring the deal and working with other countries on a new one if/when it's needed.

>I think your assessment of the outcome of said smoking gun is unrealistic. The scandal described would have massive political repercussions...

The structure of the deal gave a way to rationalize not seeing, which means some people will rationalize. That was a bad policy error, hopefully it will remain only a policy error.

>Why would it inevitably need to be renegotiated?

First, because the restrictions were temporary, starting to expire in this term. If these are needed, then they will be needed in the future. After all, The regime hasn't changed. Second, because there were other issues between everyone and Iran and not resolving these will lead to the same results as in the past.

>By honoring the deal and working with other countries on a new one if/when it's needed.

The US position is the one that matter here, so lets discuss that. The US isn't going to let other countries decide its foreign policy.

>>The structure of the deal gave a way to rationalize not seeing, which means some people will rationalize.

We're not dealing with inert subjects in negotiating partners. There is a strong motivation to counter nuclear proliferation and hold Iran to the spirit of the deal, which again is why I find your fears to be hyperbolic.

>First, because the restrictions were temporary, starting to expire in this term.

All restrictions, or some?

>If these are needed, then they will be needed in the future. After all, The regime hasn't changed.

Regimes change all the time. It's entirely posssible the Iranian regime will moderate over time. Agreements like the Nuclear Deal make that more likely.

>The US position is the one that matter here, so lets discuss that.

I'm saying US position adopted by Trump and his allies undermined diplomacy and harmed cross-Atlantic ties.

It was temporary in a sense that it applied for 10-15 years, so until 2025-2030. Whoever won in 2016 simply didn't need to worry about it in their first term. Iran did nothing to provoke it, IAEA repeatedly confirmed that, and Trump simply decided to undo it because it was Obama that reached the deal.