7/ UNSCR sanctions on Iran were never as extensive as those on DPRK or US sanctions on Iran. But - unlike unilateral sanctions - they of course obligate all Member States. The question becomes over degree of compliance. That will impact both their material and normative impact.

6/ On the latter, there's also the question of how the FATF - which used to evaluate states' compliance with UNSC targeted financial sanctions (TFS) on Iran - would proceed. The watchdog stopped assessing states' nuclear-related Iran TFS compliance when the list sunset in 2023.

5/ Snapback is meant to reimpose past prohibitions. But I can see there being some debate/uncertainty on specifics…. For example, would calls for vigilance (rather than outright prohibitions) over certain activities be reinstated? What about the list of designated individuals?.

4/ The previous UNSCRs also identified individuals and entities that were deemed to have been supporting Iran's nuclear and missile programmes. UNSCR-designated entities came under travel restrictions/bans and asset freezes.

3/ In (very) broad strokes, key sanctions/restrictions in past UNSCRs included. - Arms embargo.- Ban on nuclear/ballistic missile tech transfer.- Some restrictions/calls for vigilance on financial dealings/services.- Inspection of ships/aircraft suspected of sanctions violations.

2/ JCPOA terminated provisions of past Iran nuclear UNSCRs, namely: 1696 (2006), 1737 (2006), 1747 (2007), 1803 (2008), 1835 (2008), 1929 (2010), 2224 (2015). Not all include sanctions provisions. Best summary of the provisions of each UNSCR is by ACA:

1/ A quick summary of the past nuclear-related UN Security Council sanctions on #Iran that were terminated under the JCPOA, alongside a few observations on snapback implications.🧵

Tune in tomorrow for the live stream of the RUSI-FCDO conference: ‘The Future of Euro-Atlantic Security Architecture’. I’ll be chairing a panel on the future of nuclear deterrence in Europe with a stellar cast of experts: @ATJMattelaer, @mbudjeryn, @ProfOnderco and Paul Schulte.

Great summary thread from Héloïse (always my first port of call on French nuclear things) on the nuclear aspects of the 2025 Revue nationale stratégique, published earlier today.

The E3 will be grappling with these challenges and limitations in coming weeks. I’d argue snapback can’t be allowed to expire. But efforts need to be committed both on enforcement and on strengthening perceived value of compliance with UNSC decisions across member states. 13/.

The flip side of that is that any narratives invalidating snapback and failures to comply with reimposed UNSC sanctions will instead risk harming the authority and credibility of the UNSC. Then there’s the possibility of Iranian NPT withdrawal. Though certainly not a given. 12/.

Effects of UNSC snapback will thus be primarily normative. I still think there’s value in that. Not just for influencing Iran’s decision-making but to ensure that UNSC still carries some weight as a forum for holding states accountable and for addressing security concerns. 11/.

It’s also worth noting the relatively limited scope of pre-JCPOA UNSC sanctions on Iran. They have never been as extensive as those on DPRK. Primary squeeze on Iran’s economy has come from US - not UN - sanctions and the cooling effect they create on even non-US businesses. 10/.

In case of snapback, expect Russia, but also others, to not only fail to enforce reimposed sanctions but to also actively push a narrative of the invalidity of snapback. I’m genuinely concerned over what a push for snapback may do to the legitimacy of the UNSC broadly. 9/.

The other key questions are on the implications/effectiveness of snapback. I discussed main considerations in a piece last year, below. The deciding factor will be rate of sanctions implementation - by China and Russia, but also by other BRICS and non-Western allied states. 8/.

In light of Moscow’s tepid support for Tehran since the strikes + reported Russian openness to zero-enrichment, I’m less sceptical than I’ve been (but still sceptical) that it may support extension. I’m unsure what say - if any - Iran would have in adoption of any extension? 7/.

I’m not optimistic snapback can be avoided in that timeframe. But there are possible scenarios. For example, if E3 can’t agree among themselves on how to proceed. Or if a new resolution to extend snapback can be adopted. Latter would depend heavily on Russia and China. 6/.

Working off timelines in the JCPOA, the snapback process would likely have to be started sometime btw mid-Aug and mid-Sept. Depending on where in the process one starts and other considerations like Russian UNSC presidency. I’m working under the assumption it would be August. 5/

But would Iran also be expected to inplement AP? Resolve outstanding safeguards issues? Reach an agreement w US? . Would bet yes on the 1st and an expectation of demonstrated progress on the others, considering tight timelines and in uncertainties over state of programme. 4/.

Less clear is what constitutes “meaningful progress”. Especially given current degraded state of the programme and limited visibility. Certainly a return of IAEA inspectors to Iranian facilities and re-established visibility of equipment and materials will be expected. 3/.