The Trump administration arrived at a time of serious threats to the nuclear non-proliferation regime, particularly in East Asia and in the Middle East. The nuclear deal struck with Iran by the previous administration and its partners provides a way forward.

The established pattern of constraints on Iran’s nuclear program could be held as the gold standard for the rest of the international community. This option is readily available to the United States and the partners with which it negotiated the 2015 Joint Comprehensive Plan of Action (JCPOA): China, France, Germany, Russia, the United Kingdom and the European Union. The international community should draw on that agreement and turn its standards into general, global ones, applying them to all countries seeking to enrich uranium or attempting to use plutonium for any purpose.

So far, the deal has met the test of implementation and now shows a way forward to improve and make more durable its basic elements and structure. The key elements of the deal involve limitations on Iran’s nuclear program designed to ensure that, were Iran to choose to put it to military use, there would be sufficient “breakout” time for the international community to act. In return, Iran is relieved of much of its political isolation and given some relief from international and European sanctions. A second key element involved creating a system of enhanced monitoring and inspection, which introduced a range of both traditional and new provisions designed to provide key assurances regarding the continuing civil nature of the Iranian nuclear program.

The arrangement focused on Iran’s capacity to produce highly enriched uranium (HEU) or plutonium. The nuclear Non-Proliferation Treaty (NPT) does not contain specific commitments or limitations on these activities, except under the broadest understanding of its terms, now interpreted as generally barring the production of fissile material for nuclear weapons. Such uncertainties have been at the heart of the concerns regarding the misuse of civilian programs to move into producing fissile material for nuclear weapons. The Iran agreement is the most salient example of the international community filling that vacuum with a set of constraints and inspection arrangements. In the Iran agreement, key provisions limit Iran’s holdings of low enriched uranium (LEU) to only 300 kilograms. Iran is required not to exceed 3.67% enrichment. These limitations will stay in place for eight to 13 years. The most important limit, on Iran’s holdings of LEU, will stay in place for 15 years.

The present agreement has put in place several steps that effectively prevent Iran from separating plutonium. The purpose of these steps is to reduce the potential production of plutonium from 7–8kg per year to 1kg per year (8kg is considered a “significant quantity,” enough for a nuclear weapon). The International Atomic Energy Agency (IAEA) closely monitors these steps.

Many observers do not trust Iran, believing it is so committed to a nuclear weapon that it will use subterfuge to get one despite the agreement. They are critical of the inspection systems, of the UN and the IAEA, and of the national intelligence systems backing them up. They assert that the Iranians will soon develop a weapon and it will then be too late to stop them. Critics also argue that the agreement does not go far enough in limiting Iran’s nuclear activities: instead, they argue, Iran should have been permitted zero enrichment.

There have also been concerns regarding Iran’s ballistic-missile development and testing and Iranian activities in the region, including: Iranian antipathy toward Israel expressed in calls for its elimination; Iranian support for Hezbollah and Hamas and other entities on the US and other terrorist lists; and Iranian assistance to the Assad regime in Syria, the Houthis in Yemen and Shi’ites around the region. Other concerns include Iran’s discriminatory treatment of non-Muslims – Baha’is, Jews and Christians among them – and its human rights record in general.

Additional concerns are focused on the nuclear elements of the deal: the time limits, especially the 15-year duration of the limitation on the quality and quantity of enriched uranium.  The present agreement isolates Iran in the sense that its constraints have not been accepted by any other state, which may constitute an incentive for Iran to try to break out of these limitations. Iran has been dissatisfied with the progress and scope of sanctions removal, particularly with respect to the United States.

For most observers, these objections have not been convincing. It is true that Iran cannot be trusted: this is why unprecedented monitoring and verification procedures have been included, and why provision has been made for international sanctions to “snap back” if any UN Security Council member requests them. President Barack Obama left the door open for military action to prevent Iranian acquisition of a weapon; his successor appears to take the same view. Both the George W. Bush and Obama administrations tried an insistence on zero enrichment over many years, without bearing fruit.

Clearly, limits on ballistic missile development would be valuable. But a missile without a nuclear warhead poses much less danger, and was seen by the P5+1 as an acceptable outcome, perhaps pending a new effort in the region to create such a limitation. The existing arrangements among ballistic missile supplier states help keep these programs from developing rapidly. On regional disputes and related matters, striking a grand bargain or broader deal would have required making concessions on the nuclear limitations and inspections or additional US sanctions relief, something that the P5+1 were not interested in doing.

The objective of the new proposal is to take the key constraints in the JCPOA and make them the international standard, with respect first to uranium enrichment and then for plutonium, for all countries, including the nuclear weapons states. A new arrangement would be negotiated by the P5+1 and Iran, and by a select group of states representing potential, or technically near-term, nuclear weapons states, as defined in terms of their capacity for producing fissile material for weapons purposes. The central commitment would be to establish limits on stockpiles of LEU at 3.67% (and slightly higher at 5–6% if required to meet civil needs), with limits on stored in-country quantities as part of an effort to ensure that rapid breakout possibilities are constrained (25kg of HEU is considered a significant quantity for weapons purposes). To overcome the fact that producing fuel for power reactors will require larger numbers of centrifuges, some provision should be made, perhaps through an international fuel bank, for the monitored storage of quantities exceeding the above limits. The larger quantities of LEU needed for reactor fuel could be handled by moving it into fuel elements for domestic use or sale, or at least through conversion into uranium oxide; such steps would help keep to low levels, as does the JCPOA 300 kg limit, the amount of LEU in gaseous form readily upgradeable to HEU.

Multilateral ownership of enrichment facilities would be a useful additional way of increasing transparency. Such ownership would preserve secrecy regarding proprietary centrifuge technology, while managing the plants in such a way as to provide clear information on important activities such as production quantities and destinations of output. Monitoring and inspection techniques would be based on the JCPOA. These would include regular IAEA safeguards inspections, the Additional Protocol, and the further steps in the JCPOA such as covering uranium “from cradle to grave” as well as centrifuges and centrifuge production, and strict control over imports.

Plutonium presents additional challenges and might need to be negotiated in a second stage. While some now argue that it is important to use plutonium in power reactors as mixed-oxide (MOX) and similar fuel to speed its disposal, recent estimates indicate that costs for such fuel are in the range of ten times that of uranium fuel and perhaps much more. The right approach could be to enhance proliferation resistance by ceasing all separation of plutonium and retaining the spent fuel in long-term storage, fully protected and monitored, until such time as it would actually be needed on a cost-competitive basis for energy use or disposed of in a deep geological repository.

Objections to the agreement may come from a number of quarters. Some may believe that it should be a broader effort from the start, including plutonium as well as uranium enrichment. We sympathize with such an approach. But we also believe that our approach addresses practical necessities, such as the time required to improve the JCPOA, complications in adding two technically complicated and demanding arrangements and long-standing investments in terms of time and money on the part of a number of states in plutonium separation.

It could also be argued that bringing in states that are nuclear-armed but not regarded as nuclear-weapons states under the NPT – India, Israel, North Korea and Pakistan – ought to be a sine qua non for a successful arrangement. However, the aim here is to stop the spread of proliferation, not to reverse the course of what has already taken place.

For Russia, the UK and the US, HEU is a primary fuel for naval propulsion reactors. It is useful to note that France has developed the technology to convert its fleet of nuclear-powered vessels to LEU fuel. The principal users of HEU are, in any case, among the recognized nuclear-weapons states. The new arrangement might be accompanied by an agreement among them to continue research over the next decade or more to develop further the effective use of LEU, and over time to ensure that all new vessels brought into their fleets would be so fuelled. The US Office of Naval Reactors recently outlined a plan for the development of LEU fuel. Meanwhile, Brazil and Iran have evinced interest in developing naval propulsion reactors – presumably using HEU – meaning the time in which to act is not unlimited.

Negotiating the new arrangement will not be easy. But to have any hope of success, the P5+1 ought to give it their backing from the outset, and take the lead in bringing the idea to an international conference for negotiating an appropriate text. All of the P5 have made unilateral commitments during the 1990s not to produce additional fissile materials for use in nuclear weapons. While the P5 are not inspected or monitored internationally, national technical means provide the beginning of some transparency regarding observation of the arrangements. Limitations on the level of enrichment ought to contribute to these objectives, especially if followed by similar steps regarding plutonium. The value of having the P5 lead the work on the new agreement stems in part from the fact that they receive special treatment as recognized nuclear weapons states under the NPT. Article VI of the NPT obliges the nuclear states to move to eliminate nuclear weapons. Further strengthening the cap on the production of fissile material for use in nuclear weapons could be seen as a positive step and as critical to the success of bringing others on board.

Efforts have been ongoing in the Conference on Disarmament since the 1960s to negotiate a Fissile Material Cut-Off Treaty (FMCT).  While that treaty and its negotiation remain in limbo, the proposed new arrangement would link the P5 to provisions which would convert their own unilateral moratoriums into a binding agreement, perhaps with a national-security opt-out clause, with inspection and monitoring built on their special circumstance as recognized nuclear powers but more robust than purely national technical means.

Meanwhile, the proposed arrangement would help Iran in several ways. Iran would become the role model for the new agreement which other states would be strongly encouraged to join. It would eliminate the country’s invidious nuclear isolation. It is also true that US sanctions continue to apply to Iran in all but a few areas. Iran continues to implement effectively the JCPOA, according to regular reports of the IAEA.  Putting on the table the easing of US sanctions still in effect on the use of the dollar in the banking and financial arena, and allowing more US firms beyond aerospace to do business with Iran, would be additional incentives to bring Iran along with the new arrangement. An Iranian commitment to join the other parties in accepting a permanent arrangement with no time limit would be a welcome recognition of what Iran has repeatedly declared are its peaceful nuclear intentions.

Ambassador Thomas Pickering served more than four decades as a U.S. diplomat. He last served as under secretary of state for political affairs, the third highest post in the U.S. State Department.