There is no source for the nuclear version existing, Wikipedia has no source of a nuclear version existing. If a nuclear version of ATACMS exists it’s literally a US state secret and multiple levels of insanity would have to be limit broken for it to end up on a HIMARS truck in Ukraine.

Many levels of insanity have already been broken over the past two years if you haven't noticed. Biden himself stated that sending tanks and f16s to Ukraine would carry an unacceptable risk of escalation at the start of the war. Every red line the west has drawn for itself has been crossed. At this point, it's becoming clear that NATO is losing the war, and we're seeing increasingly desperate actions being taken.

We might as well be arguing about how you could also strap suitcase nukes to drones so Ukraine shouldn’t use drones to attack Russia either. And we know those exist

We're arguing about the US firing long rang missiles potentially capable of nuclear payloads into Russia from Ukrainian territory.

So the country of Iran still existing literally disproves this.

The problem with this argument is that Iran is not known to posses nuclear weapons.

The reality is that the old nuclear framework with MAD has been destroyed by both the US and Russia for different reasons, and as such the reality is that nobody can consider ballistic missile launches a nuclear threat. Especially since the US in 2001 unilaterally withdrew from the ABM treaty, and Russia followed suit. Lobbing cruise and ballistic missiles at your opponent has been a common occurrence in the last 20 years from both nuclear and non-nuclear states.

The destruction of treaties simply means that the risk of a nuclear exchange is much higher now. I strongly urge you to watch this interview with Theodore Postol explaining just how dangerous the current situation is. He's an actual expert on the subject. https://www.youtube.com/watch?v=RH7LT1bIdpY

Like I said if this is a real line of reasoning every Iskander used in the Ukraine theater is a reason for the US to go apeshit and say they’re going to nuke the Ukranians, we should nuke them first.

If Russia launched Iskanders into US, then US absolutely would go ape shit.

The United States would level Mexico in an instant if they ordered too much shit off of Ali Baba at this point. No one is arguing that the US is a rational actor. Russia has been extremely rational and pragmatic in this war, and to ascribe the level of irrationality you’re ascribing to them right now is to literally label them in the same way the Western propaganda has been labeling them but from a position of support.

Russia has been incredibly rational and restrained, however there comes a point where being restrained starts to look like a weakness. If Russia states red lines and then allows the west to cross these lines without consequence then it encourages further escalation. At some point Russia will be forced to retaliate to make a point. Russia unequivocally stated that there would be severe retaliation the first time the idea of deep strikes into Russia was brought up.

It is entirely likely that Russia will choose to wait a couple of months until the administration changes to see what happens. However, it's important to understand that we absolutely are on the brink of a nuclear holocaust here.

The reason the INF was even signed is because these are the riskiest platforms to actually field and maintain, the INF still allowed sea and air launched short/intermediate ranged ballistic missiles.

Well yes, no one wants nuclear weapons stationed on their land border. It's an extremely high risk scenario. So both sides at the time could agree to take these weapons out of service. Banning sea launched nuclear weapons would be an impossibility given the existence of submarines, no side would willingly give up their second strike capabilities. And air launched ballistic missiles were not operational as of 1991, the US had only conducted a few experiments and the air launched version of what became the ATACMS programme was scrapped. The Kinzhal only became operational as of 2022. Nuclear air launched cruise missiles were not going to be banned, as that was important for both sides strategic bombers.

Ultimately the treaty was not going to last with only the US and Russia being members, it's gives a superpower like China a huge advantage in this field. Even a country like Iran has developed IRBMS/MRBMs which don't have a direct NATO or Russian counterpart currently in service. There's also the plans around the "NATO missile defense system" that basically killed the deal. If one side builds missile defences, the other side is going to look to construct weapons that can bypass them, to keep the playing field level. Any future treaty would have to ban the deployment or construction of certain advanced missile defence systems to be viable.