They ARE fools.
Iran made a very foolish decision to think they could negotiate with the US by showing 60% enriched uranium as them showing "restraint".
And you know the civilization comment was made towards the regime, not the people:
Ending a civilization means ending everything in it. Infrastructure, schools, hospitals, energy production, food production. These are all things that makes a civilization. You cannot separate the regime from the people. The people support the leaders in Iran. Their leaders did not bomb them and kill hundreds of school girls like the US did. The US gave Saddam chemical weapons in the 80s which was used on Iran when Iraq attacked it. 200,000 Iranians died.
I agree, the Iranians were fools not to manufacture nuclear weapons. There is no point in negotiating with any US regime. The US is the Empire of Lies. There can be no negotiations with it.
Iran's argument is they wanted to show the world they are reasonable which is why they went though the motions of negotiating with the US. But they knew it was very likely that the US would not be a good faith actor. Most nations know now you cannot deal with US and any agreement can be ripped up a few years from now.
The best deterrent will be to develop missiles that can reach the US mainland and deliver 500kt - 1 mt nukes. Iran will need about 100-200 or more. Comparable to India, Pakistan, and Israel. I am still amazed that Russia or Pakistan has not provided any. Apparently 20% of Israel's population are Russian. So Putin appears to be just as cucked as Trump when it comes to them.