What Will Iran Do When the Sun Sets on a Nuclear Agreement?


by Peter Jenkins

Opponents of a nuclear deal with Iran have been stressing a new fear: the deal’s “sunset” provisions will result in Iran acquiring a nuclear weapon capability. This will pose an existential threat to Israel.

This concern rests in part on a misunderstanding. All the signs are that the sun will set only on a few of the agreement’s provisions. Almost certainly Iran will offer certain commitments in perpetuity: never to seek or acquire nuclear weapons, for example, and never to deny the International Atomic Energy Agency the access needed to obtain “credible assurances of the absence of undeclared nuclear material and activities” at any location in Iran.

When details of the agreement emerge it will also be surprising if Iran has not offered to limit uranium enrichment levels to 5% U235, far below the 90% needed for weapons, and to foreswear plutonium production, in perpetuity.

So what’s really at issue in a “sunset” context is the likelihood that, beginning in the late 2020s or 2030, Iran will be free to install and operate as many centrifuges as it wants, of whatever design it chooses.

For opponents of a deal this is a menacing prospect. They assume that Iran will rush to install thousands of highly efficient centrifuges, shortening the theoretical break-out time to a few weeks, and that Iran will soon acquire enough highly enriched uranium to obliterate Israel.

But these are, it is obvious, worst-case assumptions. For the last 12 years, worst-case assumptions have bedevilled attempts to resolve this dispute sensibly. So they should not be allowed to go unquestioned.

Will Iran rush to take advantage of the end of restrictions on centrifuge types and numbers?

Iran’s Quest for Confidence

For Iran the negotiation with the US and EU has been a struggle to secure respect for the sovereign rights of an independent state. It has also been a struggle to acquire confidence. We in the West are so fixated on acquiring confidence that Iran will honor its nuclear non-proliferation commitments that we tend to overlook that Iran also is looking for confidence. Iran wants to be able to rely on foreign suppliers of fuel for its reactors. It wants to know that it can get by on its own if ever those suppliers let Iran down.

Provided the nuclear agreement enshrines respect for Iran’s rights and offers Iran confidence that its nuclear reactors will be fuelled, the country may choose, come the end of restrictions, not to embark on a costly expansion of its enrichment capacity.

In November 2014 the Atomic Energy Organisation of Iran signed an agreement with Russia’s nuclear reactor supplier, Rosatom. The agreement provides for the sale of eight large reactors to Iran and for a lifetime supply of fuel for all eight of them.

That is hardly the act of a state that 15 years from now will be looking for ways of justifying a rapid expansion of its enrichment potential.

The other worst-case assumption is that, if Iran reduces its theoretical break-out time to a few weeks, its leaders will decide to embark on nuclear weapons acquisition to destroy Israel. Will they?

Diplomats and politicians who have had contact with Iranian counterparts since 1989, when Iran’s leaders opted for co-existence with the West, can testify to their possession of sufficient powers of analysis to work out what courses of action are and are not in their interests as a governing elite.

It is not credible that those leaders will ever think it worth risking their own survival to wipe out the inhabitants of the land that lies between the Mediterranean and the River Jordan, including the non-Jewish natives of the region, for whose plight they have professed sympathy. The nuclear proliferation record since 1945 suggests that the first use of nuclear weapons in a multipolar nuclear world is incompatible with the human instinct for self-preservation.

Iran’s Calculations

Those who cling to a worst-case assumption, also underestimate the importance Iran’s leaders attach to their standing in non-Western circles. Iran’s elite wants the country to be admired by other members of the Non-Aligned Movement. They do not want to jeopardize Iran’s relationships with China and Russia. They know that breaking out would give the lie to countless Iranian assurances that they have not sought and do not seek nuclear weapons, and that it would take generations for Iran’s reputation to recover from that set-back.

So there are good grounds for confidence about the post-“sunset” period. They rest on the assessment (not mine but the US National Intelligence community’s) that Iran’s elite bases decisions on rational, cost-benefit calculations.

The opponents of a deal would like to rely on eliminating the hardware (centrifuges) needed to produce weapons. But that is not a practical option. Over time, it’s the software—the calculations that determine decisions—that will matter most.

Photo: A model of Iran’s Bushehr nuclear power plant

Peter Jenkins

Peter Jenkins was a British career diplomat for 33 years, following studies at the Universities of Cambridge and Harvard. He served in Vienna (twice), Washington, Paris, Brasilia and Geneva. He specialized in global economic and security issues. His last assignment (2001-06) was that of UK Ambassador to the IAEA and UN (Vienna). Since 2006 he has represented the Renewable Energy and Energy Efficiency Partnership, advised the Director of IIASA and set up a partnership, The Ambassador Partnership llp, with former diplomatic colleagues, to offer the corporate sector dispute resolution and solutions to cross-border problems. He was an associate fellow of the Geneva Centre for Security Policy from 2010 to 2012. He writes and speaks on nuclear and trade policy issues.



  1. Iran does not need the nuclear weapon to ensure its influence in the region. Despite the sanctions, it is, with Turkey ,the most military powerful countries in the region. In fact, its experience with the 8 years war with Iraq and its involvement in Syria is far superior to Turkey that hasn’t fought a war for decades.
    Theefore Iran is the most experiences military power in the region and with the nuclear deal, its influence is bound grow to the despair of the Arab countries, especially the ones who have bought billions of dollars of US weapons roting in warehouses.

  2. Another factor that should be kept in mind regarding the Iran negotiation: The fact that the negotiation is proceeding on the basis of break-out time to produce a single nuclear weapon. With Israel in possession of some 80-300 battle ready nuclear weapons, that focus is askew from the reality of the futility of hurling a single bomb at Israel.

    Of course, that’s where the Israeli line about “the Mullahs are crazy” comes in. But it has been over 200 years since Iran launched an offensive war, whereas Israel has launched many since its founding in 1948, has acquired territory from Palestine, Jordan, Egypt, and Syria by conquest, and routinely invades the territory of its neighbors to conduct air strikes. Israel even has its “Samson Option,” whereby if it was facing imminent military defeat, it would launch all its nuclear weapons and bring down the entire Mideat. So one might reasonably postulate that Israeli government is far more crazy than Iran’s.

  3. “…..Iran wants to be able to rely on foreign suppliers of fuel for its reactors. It wants to know that it can get by on its own if ever those suppliers let Iran down”
    And that is exactly what the world did in Iran’s hour of need when facing an existential threat in a war of aggression by the Iraq. Despite full payment for the armament and signed agreements Iran did not receive the needed goods and had to go shopping for weaponry in open market through arm dealers.
    Iran like any other sovereign nation has every right to seek independence of supply of fuel for its reactor(s) if and when push come to shove.

  4. And they go kicking and screaming into the night. Israel is on the brink of being marginalized in the energy business. The Netanyahoo & gang are putting the Israeli population in the cross hairs of any mass confrontation. Collateral damage I believe it’s called.

  5. “The sunset clause” is Krauthammer’s new favorite catchphrase du jour.

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