Iranian president Hassan Rouhani at a nuclear power plant IRANIAN PRESIDENCY OFFICE HANDOUT/EPA-EFE/Shutterstock

The most ambitious effort ever to peacefully stop a country getting a nuclear bomb hangs by a thread this week. On 8 May Iranian president Hassan Rouhani announced that his country would start stockpiling low-enriched uranium and heavy water – a potential step towards building nuclear weapons.

The move was in response to US sanctions, despite Iran’s compliance with the Joint Comprehensive Plan of Action (JCPOA), which aims to limit the country’s potential bomb-making nuclear activities.

JCPOA imposed an unprecedented inspections regime on Iranian nuclear plants, which has been testing novel monitoring technology that could severely limit the spread of the bomb.


The deal does not stop Iran making enriched uranium to fuel its nuclear power plant, or heavy water for a reactor it was building at Arak. But it prevents it stockpiling either or enriching uranium further towards weapons-grade, and says Arak must be re-designed to produce less of another bomb fuel, plutonium.

The incentive for Iran was a lifting of trade sanctions, imposed after it was found to have covertly enriched uranium in the early 2000s. Since then the International Atomic Energy Agency (IAEA) has judged Iran to be in compliance with the deal.

But one year ago, US president Donald Trump pulled out of the JCPOA, saying he was unhappy with the deal. The US re-imposed trade sanctions and threatened countries that did business with Iran with severe trade penalties. Since then Iran’s oil exports have since fallen from 2.5 to 1 million barrels a day.

Now, Rouhani’s pledge means Iran will stop exporting low-enriched uranium and heavy water, which was mandated by the JCPOA, so Iran could continue production without exceeding caps on stockpiles.

The build-up of the materials will not immediately violate the JCPOA. But Rouhani added that if European countries do not, in 60 days, find some way for banks and importers to do business with Iran without suffering US sanctions, Iran will start enriching uranium further – and build Arak to existing specifications. That will be the end of the JCPOA, as Iran resumes its path to a bomb.

We may not even know if it does. The JCPOA provides three levels of safeguards in Iran. It gets the standard inspections the IAEA does in all countries with nuclear plants; additional inspections agreed in 1997 and voluntary for IAEA member states; and extra, unprecedented inspections, including continuous monitoring using novel technology.

James Acton of the Carnegie Endowment for International Peace in Washington, says that without the JCPOA, Iran gets only the basic inspections – which it successfully evaded in the past. Without extra inspections the IAEA cannot draw credible conclusions about the absence of undeclared activities in Iran, says Acton.

In theory inspectors outside Iran could watch for krypton-85, a tell-tale gas emitted when plutonium is extracted from heavy water reactors. But Acton is not even sure Iran would attempt to keep that secret. The idea of having nuclear weapons is to deter attack – and as Dr. Strangelove observed, it isn’t much of a deterrent if no one knows you have it.