Rouhani’s announcement implicitly made clear recent developments that forced Tehran’s hand. On May 3, a State Department statement said that the U.S. would sanction any individuals or entities involved with the JCPOA-permitted uranium swaps (allowing Iran to send enriched uranium out of its borders in exchange for natural uranium). The statement also noted that the storage of heavy water in excess of current limits would not be permitted by the United States, nor should “any such heavy water … be made available to Iran in any fashion.”
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In effect, however expensive continued compliance with the deal might have gotten for Iran after the Trump administration reimposed sanctions last year, the U.S. had now sought to change the very terms of compliance—even though it is no longer party to the pact. The remaining countries, try as they might, have been unable to present Iran with a sufficiently robust solution that would work around the reimposed sanctions.
As a result, Rouhani’s decision to underscore that at the end of the 60-day period Tehran might overshoot existing heavy water and low-enriched uranium limits conveys precisely to the E3, Russia, and China where the blame for its decision should rest: with the United States. Make no mistake: These steps announced by Rouhani would measurably degrade the nonproliferation effectiveness of the JCPOA and, over time, breaking the enriched-uranium-stockpile limit in particular would serve to shorten Tehran’s breakout time to a single weaponized nuclear device, if a political decision to pursue that path were to be made. Because all the remaining parties to the agreement would seek to avoid that outcome, Iran might hope it is creating the right set of incentives for the E3, Russia, and China to independently seek a rollback from the United States.
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The E3+2 remain committed to preserving the JCPOA as agreed in 2015. However, where Iran might have miscalculated in an attempt to increase the urgency with which the remaining parties react is in what it said will come after the 60-day period. Rouhani announced that should the remaining parties fail to fulfill their commitments to Iran—specifically on oil and banking, two areas hit hardest by last year’s U.S. sanctions—Tehran would also cease observing JCPOA limits of enrichment levels and roll back modernization of the heavy-water IR-40 reactor at Arak. These measures raise the greatest proliferation concern, and Iran’s following through on them would take the JCPOA past a point of no return. Most importantly, if the International Atomic Energy Agency were to find Iran in violation of these commitments, the E3+2 might find it difficult to avoid a referral to the UN Security Council to “snap back” pre-2015 nuclear sanctions on Iran. This was always intended to serve as a measure to punish Iran for noncompliance; its use would be agnostic to the reasons why Tehran chose to abjure its commitments. Moreover, the Trump administration would get a vote, given the U.S. seat at the Security Council.