Explainer: What Iran and world powers agreed in Geneva

The agreement reached in Geneva between Iran and the P5+1 (China, France, Russia, the United Kingdom, the United States, plus Germany) represents a modest but important "first phase" deal, which is designed to constrain Iran’s nuclear potential while seeking “a mutually agreed long-term comprehensive solution that would ensure that Iran’s nuclear program will be exclusively peaceful.”

The deal, spelled out in a Nov. 24 “Joint Plan of Action,” will verifiably halt and, in some areas, roll back progress in Iran's nuclear program, which has the capacity to produce material for nuclear weapons. The agreement also significantly bolsters International Atomic Energy Agency (IAEA) monitoring capabilities at key Iranian nuclear sites to detect and deter noncompliance.

In exchange, the P5+1 states will extend limited, reversible relief from certain sanctions now in place, including the repatriation of $4.2 billion in frozen Iranian oil revenue, and a pledge not to impose new nuclear-related sanctions for the duration of the agreement if Iran abides by its commitments. The core of the existing international financial and oil sanctions regime will remain in place.

Implementation of the first-phase agreement, which is to begin before the end of the year, will significantly increase the time it would take Iran to amass enough fissile material to build nuclear weapons. The agreement also provides for unprecedented transparency measures, including daily IAEA inspections at the Natanz and Fordow enrichment facilities, which would enhance existing safeguards against any move to create weapons-grade nuclear material.

The Geneva agreement is designed to last six months but could be extended by mutual consent of the parties. Its goal is to create more time, and a more cooperative climate, for negotiating a “final phase” agreement. That agreement would include measures to significantly reduce Iran's overall enrichment capacity according to a "mutually defined enrichment program” with “agreed limits on scope and level of enrichment, activities, capacity … and stocks of enriched uranium." The final phase deal would likely allow even more intrusive IAEA inspections to guard against possible secret nuclear weapons-related activities.

Iran has agreed to several important constraints on its uranium-enrichment program, as well as on its Arak heavy water reactor, which if brought online would produce plutonium that could be used to produce weapons. The agreement requires that Iran:

• Halt uranium enrichment to 20 percent levels, which is above normal power reactor fuel grade (3.5 percent) and closer to weapons grade (above 90 percent) by measure of enrichment time-scale.

• Neutralize its existing stockpile of 20 percent enriched uranium by oxidizing or diluting it. Currently Iran has 196 kg of 20 percent enriched uranium. Tehran would need just 250 kg, if further enriched to weapons-grade, to produce one bomb. Iran must disconnect equipment that could reverse the oxidization process.

• Cap the stockpile of 3.5 percent low-enriched uranium (now at 7,153 kg) by oxidizing a portion equivalent to whatever additional amount it produces.

• Freeze Iran’s current enrichment capacity by halting the installation and operation of additional centrifuges at the Natanz and Fordow plants, including more advanced IR-2m centrifuges. Iran has approximately 10,000 IR-1 machines that are operating; 19,000 are installed.

• Freeze any further advances on the uncompleted Arak heavy water reactor, including a halt to the production, testing or transfer of fuel or heavy water for the reactor or the installation of any reactor components. The reactor, which is still a year or more away from completion, would have to operate for another year to produce spent fuel laden with plutonium. Iran also agreed not to construct a facility capable of separating plutonium from the spent fuel.

In addition, Iran has committed to new transparency measures. Iran will for the first time:

• Allow daily, rather than weekly, access by IAEA inspectors at Natanz and Fordow.

• Grant IAEA access to centrifuge assembly and production facilities, to guard against any effort to build a secret enrichment facility.

• Provide earlier notification and information regarding any new nuclear facilities.

• Provide updated design information on the Arak reactor and more frequent on-site inspections at Arak.

Once these restrictions are in place, Iran would find it extremely difficult to make an undetected dash to build nuclear weapons using its major facilities.

In exchange for Iran taking the concrete steps listed above, the P5+1 will:

• Release approximately $4.2 billion of the estimated $50 billion in Iranian assets tied up in other countries from oil sales.

• Waive certain sanctions on trade with Iran’s auto sector, petro-chemicals, and trade in gold and other precious metals just put into effect last July. This will provide Iran with approximately $1.5 billion in revenue.

Over the six-month span of the agreement, however, Iran will remain under severe international sanctions and additional Iranian financial assets — perhaps as much as $15 to $20 billion worth from oil revenues — would become frozen as a result of ongoing financial sanctions, providing world powers with substantial leverage in ongoing negotiations.

The U.S. intelligence community believes that Iran has, since 2007, had the technical capacity to produce nuclear weapons, but that it has not yet chosen to do so. If it made such a choice, according to the U.S. assessment, it would take Tehran “over a year” to build a bomb.

Through the negotiation process, the U.S. and its allies have sought to expand the time-frame — and the barriers — faced by Iran in “breaking out” of the nuclear Nonproliferation Treaty (NPT) to build nuclear weapons. That includes enhanced ability to promptly detect and effectively respond to a breakout, at the same time as diminishing Iran’s incentive to pursue nuclear weapons in the future.

The first-phase agreement puts in place measures that, if implemented, effectively cap the progress of Iran’s nuclear program in all key areas and roll back Iran's theoretical nuclear weapons breakout capability.

By halting 20 percent enrichment and neutralizing the existing stockpile of material enriched to that level, as well as freezing the number of centrifuges available for enrichment, the Geneva agreement will add at least a month to the time theoretically required for Iran to produce enough weapons-grade uranium for a single nuclear weapon. Without the implementation of the first-phase agreement, by 2014 Iran could reduce this time-frame to as little as two weeks — which potentially allow it to create a bomb’s worth of material before inspectors could detect such an effort.

The Geneva deal opens the way for negotiations on a comprehensive, final-phase agreement to further roll back Iran's overall enrichment capacity; blocks the plutonium pathway to the bomb; and resolves outstanding questions about possible military dimensions to Iran’s previous nuclear research work — in exchange for ending all nuclear-related sanctions.

The key question is the extent to which Iran is willing to reduce the capacity and the scope of its uranium enrichment. The Nov. 24 agreement states that Iran’s enrichment program should be “consistent with practical needs,” meaning its capacity and stockpile of material should not exceed the fuel supply needs of its energy-producing nuclear reactors. Those are currently close to zero, but could grow in the coming years.

Iran will insist on retaining some uranium enrichment capacity, to which it claims a right as a signatory to the NPT, which codifies an “inalienable right to the peaceful use of nuclear energy.” The U.S. and some other P5+1 states do not believe that states have an “right” to uranium enrichment, a technology that can be used to produce bomb material, especially if they may have engaged in nuclear weapons-related research.

Thus, the two sides did not resolve the nature of Iran’s nuclear energy rights, but resolved to negotiate practical limits and further safeguards on Iranian enrichment activities.

Given Iran’s limited need for enriched uranium to fuel energy production, a reduction in Iran’s overall enrichment capacity — from 10,000 operating centrifuges at two sites to 3,000 or fewer at one site — would be more than sufficient for Iran’s potential needs. That, together with limits on Iran’s enriched uranium stockpile, would increase the time-frame necessary to produce enough material for one bomb to six months or more.

The P5+1 states would also like Iran to abandon the unfinished Arak reactor, which represents a long-term proliferation threat, but Iran will likely resist such an outcome. One compromise might be to convert Arak to a more proliferation-resistant light-water reactor, or agree to verifiably remove the spent fuel for disposal by a third country — possibly Russia — to prevent it from becoming a source of plutonium.

The P5+1 will also seek to persuade Iran to allow even more extensive IAEA inspection authority to guard against a secret weapons program under the terms of the Additional Protocol to its existing safeguards agreement. This would allow the IAEA access to non-declared sites without prior notification, which is a strong deterrent against any clandestine nuclear weapons work.

To resolve longstanding questions about suspected weapons-related experiments that may have been conducted in secret in past years, Iran will also need to fully cooperate with the IAEA. On Nov. 11, the IAEA and Iran agreed to a new approach to the long-stalled investigation about these experiments, including possible high-explosive testing for warhead designs, and whether any such work been terminated.

To secure a "final phase" agreement, the P5+1 will need to further scale back the oil and financial sanctions that are devastating Iran's economy, which will require action by the European Union states and Congressional approval of revised sanctions legislation.

Negotiating an agreement along these lines will be difficult. Implementing those steps will be even harder.