A few thoughts on this story, which asserts the US may claim to remain a participant in the JCPOA in order to exercise its snapback provision if the UN Security Council fails to extend the arms embargo on Iran. 1/ https://twitter.com/SangerNYT/status/1254532939964088331

First, the justification arises from the text of UNSCR 2231, op10 of which defines "JCPOA participants" as China, France, Germany, Russia, the UK, the US, the EU, and Iran. 2/

However, as I've stressed repeatedly, interpreting UNSCRs is a fundamentally political, not legal, matter. The other parties do not simply differ with the US reading of the text (which they do), but believe the JCPOA serves their interests. 3/

This raises the Q of what impact snapback will have. We can really only speculate, because this is a novel mechanism not previously used in UNSCRs - the Obama team touted it as an enforcement backstop, but didn't imagine this scenario. 4/

It seems unlikely that snapback will add appreciably to the sanctions pressure on Iran, simply because it is already so considerable. US secondary measures are effectively honored even w/o a UN-blessed basis. 5/

It also seems unlikely that snapback will deter Russia and China from selling arms to Iran - that again will fall to US sanctions, which are more likely to affect the Chinese than Russian calculus. 6/

Exercising snapback when other states - including our European allies - view it as illegitimate could deepen the already considerable transatlantic wedge on this issue, which Iran may regard as a political victory, albeit one that doesn't put bread on the table. 7/

Ironically, whether it causes the JCPOA to "die" likely depends on Iran itself. If it continues to honor it, the chances of a future US administration returning to it - and of other parties working to preserve its benefits as they see them - remain. 8/

If Iran discards its JCPOA obligations in response to snapback, then it is less likely a future US administration could revive the deal, and more likely other states (Russia, China, and a few others excepted) would resume sanctions. 9/

The question for the US - why not put a diplomatic proposal on the table for Iran to accept or reject? If it does the latter, as is frankly most likely, you are in a stronger position to argue for snapback and sanctions enforcement. /End