The United States hopes talks with Iran in Geneva on Thursday will produce an agreement to end or reduce Iran's nuclear weapons program substantially below what it was coming out of the 2015 Obama-era nuclear deal, as well as to reduce the threat of Tehran's ballistic missile program.
US President Donald Trump has amassed the largest buildup of American forces in the Middle East since 2003 to increase pressure on the Islamic Republic to reach a deal, with the open question being whether the two sides' redlines can overlap just enough to avoid a broader war.
Israel would only support a deal that neutralizes both the nuclear and ballistic missile threats, whereas Trump has signaled readiness to reach a deal even if he achieves less than fully neutralizing those threats, especially regarding ballistic missiles, as long as he can portray his achievements as far beyond Obama's.
What is at stake?
Iran has, over the decades, developed an advanced and large-scale uranium enrichment program. While enriched uranium can be used as fuel in power plants at various purity levels, at high levels it can be used to make nuclear weapons.
Until Israel and the US attacked its nuclear facilities last June 2025, Iran was enriching uranium to up to 60% purity, a short step from the roughly 90% that is weapons-grade.
It had enough material enriched to that level, if enriched further, for 10 nuclear weapons, according to an International Atomic Energy Agency yardstick, and more at lower levels.
That material is one of the few elements of the nuclear program that was not destroyed last year, with virtually the entire fleet of 20,000 uranium-enriching centrifuges damaged, all weapons program items damaged, and most of the top nuclear scientists killed.
Iran has yet to declare what happened to its enriched uranium or allow the IAEA nuclear watchdog agency to inspect its bombed nuclear facilities. However, Israeli officials have said that they know the whereabouts of the enriched uranium, and other sources have indicated that most or all of the uranium was buried under rubble from the nuclear sites bombed in June 2025.
What do both sides want?
Enrich elsewhere: In previous rounds of talks, the idea of a regional enrichment consortium was floated, involving a joint venture with one or more other Middle Eastern countries outside Iran. To date, Tehran has always rejected that as an alternative to enriching on its soil.
Enrichment to a low level: It becomes exponentially easier to enrich to weapons-grade the more highly enriched uranium you start with. In terms of effort, once you have enriched to 5% purity, you are more than halfway to weapons grade.
Keeping Iran at arm's length from being able to race towards nuclear weapons will involve limiting the purity it can enrich to and how much enriched uranium it can amass.
The 2015 deal let Iran enrich to 3.67% purity. Diplomats have said, only half-jokingly, that Trump's rejection of that deal is so great that 3.67% is the only enrichment level he will not accept now.
The latest leaks have indicated that Iran is prepared to commit to zero enrichment for a period of years, with negotiations between Tehran and Washington over whether that period would be three, five, seven, or 10 years.
Even after that period, the Trump administration would demand enrichment at some level below 3.67%.
Iran has demanded that it not give up the right to enrich, but showed greater readiness regarding limits, especially since it currently lacks the machines to enrich uranium.
If Trump agreed to allow such a deal, the US would likely demand far more invasive IAEA inspections than previously existed to ensure the regime's compliance.
Alternatively, Trump may decide that, absent an end to enrichment, he prefers to attack Iran.
What else needs to be addressed?
Any deal would also have to require thorough accounting for Iran's stock of enriched uranium. Any doubts about that could trigger a new conflict.
As in 2015, a deal would most likely require diluting or removing enriched uranium and would limit the number of centrifuges and where they can be used.
Little has been discussed about ballistic missiles.
The US, at a minimum, would likely want Iran to stop activities that could lead to developing intercontinental ballistic missiles (ICBMs), which could eventually strike the continental US.
Israel wants the range of ballistic missiles to be cut to below 1000 kilometers so that they will no longer be able to reach the Jewish state.
Alternatively, Jerusalem wants to preserve its right to strike the Islamic Republic's ballistic missile program, even if the US promises not to strike, in the event that the ballistic missile program is not sufficiently curbed to avoid threatening Israel.
Reuters contributed to this story.