Key points from the JCPOA:
- Centrifuges reduced to 6104, with 5060 able to enrich uranium and all of them are IR-1, Iran's first generation and least capable centrifuge
- A major reduction (97%) in Iran's LEU (low-enriched uranium). While it remains unclear how exactly this will happen, it is believed that this will be due to a mixture of dilution and shipping extra stocks out of country (probably to Russia)
- All excess centrifuges will be put into IAEA monitored storage
- Fordow will be converted and heavily restricted from nuclear activities for 15 years
- Iran's later generations of centrifuges will not be used for 10 years
- IAEA will have 'regular' access to all of Iran's nuclear facilities (including Natanz and what will be a formerly nuclear site, Fordow)
- IAEA will have access to the supply chain and will also have access to and surveillance of uranium mines and mills for 25 years
- Iran will sign the Additional Protocol of the NPT
- Arak will be redesigned, and made incapable of producing weapons-grade plutonium and its core will be either destroyed or taken out of country
- Iran will receive sanctions relief IFF it abides by the terms (IAEA will address enrichment, Fordow, Arak, PMD, and transparency)
- IAEA has to VERIFY Iran has taken the right steps before sanctions are removed
- US Sanctions on Iran for human rights, terrorism, and ballistic missiles remain in place
A common refrain from hawks is that Iran has refused to address PMD (possible military dimensions), and has worked on developing its ballistic missile program. These concerns are valid. They've also worried about IAEA access to sensitive sites, and centrifuge R&D.
There are clauses in the JCPOA (Joint Comprehensive Plan of Action) which address all of these. If this is in fact accurate, the deal looks to be quite good.
There are a few drawbacks included, such as the continuation of enrichment at Natanz, though limiting the enrichment to a relatively low number of first generation centrifuges strictly limits Iran's enrichment capabilities. Jeffrey Lewis wrote here about the type of centrifuges used and how the number of total centrifuges operational is less important than how modern the centrifuges are.
Another possible downside to the JCPOA is the removal of sanctions. It remains unclear exactly under what circumstances the sanctions would be removed, how they would be removed, and if the conditions of removal are violated, how and how quickly the sanctions would be reimplemented. It seems as though only nuclear related sanctions are to be removed, which leaves quite a few sanctions left over.
Hardline Iranian editor Shariatmadari on the Lausanne understanding: "We've given them a horse with saddle and received back its corpse."If the most anti-American factions of the Iranian elite are upset with the deal thinking they gave up too much, then it is a good deal for the West.
— Saeed Kamali Dehghan (@SaeedKD) April 2, 2015