Eh. Iran is no more likely to pursue developing nuclear weapons now, than they were before. Because they were already doing so. Any arguments to the contrary are semantic. We know with certainty they have enriched uranium to 60% and we also know there is no peaceful purpose for them to do so. If you want to assert they have the right to do so when faced with Israel, and if you want to assert that their leadership is stable and non-threatening, you can do so. Plenty will disagree with you, but it's a least a defensible position. What can not be asserted, is that they have not been pursuing nuclear weapons development. There's no reason for them to enrich uranium to 60%, and there's no reason for them to hide "peaceful" uranium enrichment facilities in bunkers under 200 feet of reinforced concrete. No action taken by the USA or Israel within the past 2 months, is going to make Iran any more likely to continue their ongoing pursuit of nuclear weapons.
I've also seen the flipside argument, that the USA's apparent pull-back from NATO support with respect to Ukraine, is going to signal to our NATO and world allies, that the US nuclear umbrella no longer protects them. And so Germany and other countries, are now going to be more likely to develop their own nukes.
The truth is that it's difficult, and expensive, to do it. Most of those countries won't even spend the 2% of GDP in a defense budget for conventional weapons. They're not about to go out and create nuclear programs.
It's hard to make nukes. And there are only a tiny handful of countries that would even try. They're all well-known, and closely monitored. And given that Iran's traditional allies and puppets are not demonstrating any support for them right now, it's pretty clear to me that the rest of the world isn't in mood to tolerate new nuclear powers arising.
As far as the enriched uranium goes- while it's true they had enriched uranium to 60%- they only started doing so after Trump unilaterally withdrew the US from the JCPOA in 2018. Every bit of enriched uranium that Iran had produced while the US was in JCPOA was being sent off to France to make fuel rods and shipped back into Iran for use in nuclear power generation. The DIA threat assessment in March found no evidence that they had an active nuclear weapons program or were trying to build one. And the supreme leader of Iran has still not reversed his 2003 fatwa banning nuclear weapons in which he stated nuclear weapons were incompatible with Islam and declared them illegal by Islamic law. That might seem like a small thing- but it was the binding legal & religious law of their land and they have not changed that law. And Iran is still signatory to the NPT and are still in parts of the JCPOA, they have not withdrawn from either and kicked out all IAEA inspectors. Yet. They just might now.
Iran had been getting choked to death by the reinstitution of sanctions and by newer even tougher ones Trump slapped on them when he ripped the deal up in 2018, they were trying desperately to get back into some kind of deal with the US. They didn't want war with the US. They wanted a deal. They have the 3rd most oil reserves on planet earth- they'd like to actually be able to be part of the global trade system and unlock that oil. And they didn't just go right to enriching 60% right away. The first year the US left the deal Iran stuck to the JCPOA and were enriching only to 3.6% and sending everything off to France. They gradually started to slowly move the needle up as pressure was coming in on them from all sides and were trying to get a deal with the US. It wasn't exactly like- hey boom we're going to 60% over night the next day. At first they went to 20% and were maintaining there and did not start enriching to 60% until after Israel attacked one of their facilities in 2021. They didn't start enriching to 60% uranium until almost three years after Trump nuked the JCPOA. And they haven't gone higher since. It's been 4 years since they were enriching 60%, they could've went to weapons grade by now if they wanted. That suggests to me they don't want to because of the potential problems it could uncork for them had they done so- ie an imminent all out attack by the US. Why else would they just maintain at 60% for 4 years if they were really trying to build a bomb? What they had was a latent nuclear threat deterrent. The 60% enriched uranium was there as leverage to give away in negotiations with the US for a new deal- just like it was there in 2015 to give away when virtually the entire world spearheaded by the US made the deal with Iran on it's enrichment program. It was there as a latent deterrent and as a chip in negotiations to deal away.
This is also something that is not talked about enough but incredibly important in this entire discussion- they
have no route to a plutonium bomb. While it's true they could get to 90%+ enriched uranium in a matter of months (before this) they would still have to build and develop a uranium gun type bomb- which is massive and would not fit onto any kind of war head they have or could build. They do not have the facilities required to take the plutonium waste from their nuclear reactors and reprocess the plutonium into weapons grade fuel. They are still in parts of the JCPOA and as part of the JCPOA Russia comes in every couple years and removes their plutonium waste and takes it back to Russia. They have no route to a weapon that could fit on a delivery system and they completely lack the delivery system to hit the US. Again they flat out just do not have a route to a miniaturized plutonium bomb that could be fitted to a war head and....they don't have ICBM's that are capable of reaching the US. As it stood before the US went on it's bombing run they just were not an actual credible imminent threat to the US in any way shape or form in a million years.
As for why they might build these facilities in bunkers underground, well Israel has been attacking their above ground facilities and assassinating their scientists for decades. This isn't a new thing for them- they had done same thing to Saddam and his facilities and scientists in the 80s and 90s when he was ruling Iraq. I'd assume that's probably why.
Do a thought experiment for a second. You're an Iranian living in Iran. Israel doesn't have a
hypothetical nuclear weapons program. They
actually have nuclear weapons. Hundreds of them. Their Prime Minister has been openly talking about invading and bombing your country and assassinating your leaders since 1992. They have the most powerful military force in the history of planet earth (us) as their express guarantor and backer supplying them with infinite advanced weaponry- much more lethal and advanced than anything you have. They aren't in the NPT, they've got nuclear weapons, and they have been bombing and assassinating your leaders for decades. When is the last time Iran openly just attacked Israel on their soil without provocation? Like never. Israel attacks Iran on their soil whenever it feels like with impunity and has done so for decades. Netanyahu had been planning to attack Iran back before Trump was ever elected into office and recruited him to this attack. The reporting on this has been coming out the last few days and it's both fascinating and scary.
Iran has agreed to having a nuclear weapons free zone in the middle east. It is Israel which rejects this in whole. Israel won't sign the NPT nor let UN/IAEA/US inspectors anywhere near any of their nuclear facilities. They deny they even have a stockpile of hundreds of nuclear weapons. And unlike Iran- they actually have the capability to make a plutonium bomb that would fit on a missile and the delivery system to use it. Again...something Iran doesn't have. What are Iran going to do if they had a crude uranium gun type bomb? Drive it on a flat bed into Tel Aviv?
As for your last sentence, it's pretty obvious to me that like the US, Russia and China both do not want to see the proliferation of nuclear weapons. Russia has it's hands full in Ukraine and bit off more than it can chew there. And Russia is also a supporter of Israel- it's not like they are anti-Israel, there are 1.6 million ethnic Russian Jews/Russian speakers/descendants of Russians living in Israel- it's around 15% of the country. And Israel is actually one of the few close US allies that hasn't sanctioned Russia into oblivion over their crimes in Ukraine.
I also have my doubts the NATO free loaders are going to pony up. They just announced 5%....believe it when I see it.
Speaking of Ukraine- that war has to end, the dying has to stop. Trump has promised to end it in 24 hours. He needs to get a deal worked out and get it ended for good. And I am 10000% against nuclear weapons but I think at this point it's pretty safe to say that had Ukraine not given up it's nukes Russia wouldn't have invaded. Looking back- that was a tragic strategic mistake on their part. And sadly the message to the rest of the world that isn't in NATO or vital to US interests seems to be if you have nukes you won't get invaded- if you don't- there's a good chance someone will bully you. That's a complete failure of the international order and needs to be addressed/fixed. I'd like to see Netanyahu & Putin sharing a bunk in a jail cell when the wars in Gaza and Ukraine end. Never going to happen but one can dream.