The head of the Atomic Energy Organization of Iran, Ali Akbar Salehi, did say that Iran could start enriching uranium up to 20% within 4-5 days of the Joint Comprehensive Plan of Action breaking up.
Reporting on these comments suggests that Salehi means that Iran could have fissile material sufficient for a nuclear weapons in that timeframe, but that is a false interpretation. There remains a huge discrepancy of time and capability between when Iran would start enriching uranium at a higher level and when they would achieve that level of enrichment. And there is another gap between getting that capability online (acquiring, installing, calibrating, running centrifuges) and when the country would be able to accumulate enough fissile material for a nuclear weapon.
Additionally, the JCPOA bans Iran from enriching uranium above 3.67% for any purpose. So 20% enrichment on Iran’s part would be a clear violation of the deal. It is also important to note that in order to be suitable for nuclear weapons, uranium must be enriched to 90% U-235, requiring a significant additional investment of time and energy beyond what Salehi claimed Iran would be capable of in this scenario.
Therefore, Iran’s breakout time, as guaranteed by the JCPOA, is not 5 days but rather more than a year should they decide — or be provoked — to abandon the deal. And the JCPOA ensures that that year+ breakout time is in place for more than a decade.
Finally, in context, Salehi’s comments were directed toward encouraging the United States to abide by the deal despite our President’s many threats to the contrary. In the same remarks, he said, “We have not achieved the deal easily to let it go easily. We are committed to the deal, and we are loyal to it.” But much as the U.S. is prepared to snap back sanctions if the deal is violated, our Iranian counterparts want to be clear that they have their own snap back capabilities — and remind us that through reckless threats we push them back toward the behavior we sought to avoid by negotiating the agreement in the first place.
If Iran does begin to enrich uranium to 20% unprovoked by an American breach of the deal, that will constitute a violation of the JCPOA and the international community will join with the United States to respond by reinstating sanctions. However, if the U.S. violates the nuclear deal first, such as by snapping nuclear-related sanctions back into place without cause, other nations — even longtime allies — will have a hard time supporting that position. Such a divide between the U.S. and our European allies could be one of the most damaging outcomes of the Trump Administration’s Iran policy.