With the UK, France, and Germany starting the 30-day process on Thursday to "snapback" global sanctions against Iran, the hammer is closer to falling on the ayatollahs than ever.
The "snapback" is a mechanism built into the 2015 JCPOA nuclear deal that allows any of the parties to the deal to automatically bring back full global sanctions on Tehran if they view it as materially violating the deal, with Russia and China lacking their standard UN-style veto power.
The E3's decision follows two months of negotiations since the June war between Israel and Iran, in which the Israeli and American air forces set back the Islamic Republic's nuclear program by around two years.
Although Iran has been sanitizing nuclear sites since then, there are no signs that it has made any progress toward reconstituting any of the many aspects of its nuclear program that Israel and the US struck.
And yet Iran's Supreme Leader Ayatollah Ali Khamenei has not yet shown much of an inclination to make the concessions necessary to avoid the snapback and possibly even additional air strikes by Israel and the US.
To date, the only real concessions that Khamenei has made is to allow the IAEA nuclear inspectors back into the country, but even then it has only been co entirely civil nuclear sites, such as the Bushehr facility.
In contrast, Iran has refused throughout the two months to allow the IAEA access to any of the military nuclear sites which Israel and the US struck, including the around 400 kilograms of enriched uranium which were not struck.
It is still unclear what Khamenei's game plan is at this stage.
There is still time for Khamenei to make concessions, as if he reaches a new comprehensive nuclear deal or an interim agreement to postpone the showdown within 30 days, the snapback will not actually take effect.
Iran agreeing to extend the expiration of the snapback beyond October 18 remains the most likely outcome in the next 30 days, which would allow the E3 to give Tehran more time to negotiate.
It would be a hard concession for the Islamic Republic to swallow, but likely preferable as compared to global sanctions and the enhanced threat of Israeli and American attacks, as well as preferable to rushing to make larger big picture concessions, such as agreeing to restrict its uranium enrichment.
This would allow Iran to buy time.
Khamenei also has little to retaliate with against the West at this point against global sanctions.
He can pull Iran out of the Non-Proliferation Treaty (NPT), but then what?
If before June, he could activate more centrifuges and enrich more uranium, Jerusalem and Washington's forces made all of those facilities go up in smoke or caved in under massive rubbles of rock.
So Iran pulls out of the NPT, but then can do nothing. Not much leverage.
It could throw out the IAEA, but it has already done that in stages over three years. And until it lets the IAEA visit military nuclear facilities, its cooperation is not worth much.
Iran to seek support from Russia, China?
Khamenei could hope that support from Russia, China, and some other countries will keep his country afloat despite global sanctions.
When global sanctions were on Iran before 2015, the world was more dependent on the US and the West.
Russia and China have already decoupled much of this since Moscow invaded Ukraine in 2022.
But regardless of whether global sanctions would completely throttle Iran's economy or only partially over time, it would be another major body slam economically to an economy that is already weakened by years of partial sanctions and by the June war.
This is why Iran will probably eventually decide to extend the "snapback" for around six months as proposed by the E3.
Whether it will do so before the 30 days expire, or ask to do so after the snapback starts going into effect, in order to freeze its effect, is more of an open question.