I hope these negotiations on nuclear capability are just to stall a bit during military buildup, and theoretical nukes by 2052 won´t become the official casus belli. US should've bombed the shit out of the islamists 50,000 casualties ago.
This had better end with Iran de-nuked.
Taking out Iran swiftly and overwhelmingly is a way to show Russia and China that we aren't playing around anymore. Overrunning Iran quickly is a win on multiple fronts.
IT removes a regional ally and grey-market handover zone, and a coutnry that sells them both resources in exchange for military hardware.
If things go maximum hilarity and we get US bases in Iran, this is a huge issue for China who now has to defend their west but especially Russia.
to tl;dr: Once the US withdrew from Afghanistan, Russia figured they could pull all but the barest of their air defense from the remote center of the country and ability to do this was a big factor in their decision to go into Ukraine (the expectation was Russian AAD plus captured Ukrainian systems would put up a potent enough barrier that there was no way NATO would challenge it). Ever since, that AAD has been needed to suppress Ukrainian airpower and drone/missile attacks. US bases in Iran means Russia has to start bring back those Anti-air systems and radars or risk that US could could cut the country in half as well as have strike ability on the "Ground and Silo based" arm of Russia's nuclear triad.
A ground war in Iran will destroy America completely so not a bad gambit by the mullahs.
OTOH America clearly isn't preparing for a ground invasion. The numbers are bigger than the lead-up to Afghanistan but way smaller than Iraq 2. All signs point to bombing the fuck out of them and hoping the domestic insurgency handles the infantry role.
I think you're over estimating that if the US did decide to invade Iran, what said invasion would look like. For starters it woudn't just be the US. Turkey would almost certainly be brought on board, so would Saudi Arabia. Egypt would very likely be tapped for contributions.
The real hilarity would be the almost certainty of Azerbaijan and Armenia ending their 30 years of war and then going to fight Iran shoulder-to-shoulder.
At current I don't think India would offer any real support; while Modi would love to have an excuse to bust out the Curry Carrier and big-dog on the world stage, Iran and Pakistan are currently on the outs diplomatically.
I've not been keeping up enough to cut through the bullshit, but South Africa would likely sign up for peacekeeping in exchange for political & trade concessions. I know the SAG is pissed at Trump for highlighting Boer genocide but I'm not sure how pissed.
I'm not sure what Milei's stance would be, but he owes Trump bigly so we might see Argentina contribute. Chile almost certainly would.
Columbia would most be PMCs at current.
When discussing this elsewheres, someone else said Morrocco would be onboard but I got no evidence for that.
Turkmenistan might possibly join in.
In addition to Turkey, we'd see NATO troops, mostly Eastern NATO.
Anyway this long and gay way to emphasize:
It woudl not just be the US army if Iran was getting the Iraq treatment.
I guess let me posit this to you:
Iraq in 2003 fell to the US in 4 weeks. That was a country that granted had 1/3 the population of Iran but didn't have active protests several times a decade. If the US was going to go Regime Change Hard on Iran, whichis already roiling with internal descent, how long do you think Tehran holds out?
The only real issue is what would happen after the Iranian government implodes as you touch on. And that's why there is the footdragging.