Explainer: Issues in Vienna Nuclear Talks

On April 6, the world’s six major powers launched new diplomacy in Vienna to get the United States and Iran back into full compliance with the 2015 nuclear deal. The logistics were unusual because Iran refused to meet directly with the U.S. delegation. So the Joint Commission—the body tasked with overseeing implementation of the Joint Comprehensive Plan of Action (JCPOA)—sponsored the talks that included Britain, China, France, Germany and Russia. The sessions were chaired by Spanish diplomat Enrique Mora, representing the European Union. Delegations from Iran and the United States worked out of separate hotels and communicated via European envoys who shuttled messages back and forth.

The process contrasted sharply with the talks between 2013 to 2015 that led up to the JCPOA, when Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif talk face-to-face. Their working relationship was instrumental in brokering the deal.

This time, diplomats broke into two working groups—one on steps the United States needs to take to lift sanctions and the other on steps that Iran needs to take to roll back breaches of the nuclear deal since 2019. A third group worked on sequencing issues. The Biden administration called for two countries to fulfill their obligations simultaneously—what U.S. officials have called “compliance for compliance”—while Iran demanded that the United States lift sanctions first since President Trump had withdrawn from the deal in 2018.

The first sessions in Vienna took place between April 6 and 9. The second went from April 15 to 20. Both the United States and Iran signaled movement. “The talks have been businesslike,” State Department Spokesperson Ned Price said on April 20. “But there remains a long road ahead.” On April 19, Iranian Foreign Ministry Spokesperson Saeed Khatibzadeh said that the talks had reached a “difficult and complicated stage” but were “on the right track.” On April 21, President Hassan Rouhani said that U.S. officials “appeared to be serious” about lifting Trump-era sanctions but spoke “equivocally” about some steps. “Now we should see,” he added. A third round of talks was held from April 27 to May 1. A fourth round began on May 7. The following is an explainer of the two main issues in the talks—lifting U.S. sanctions and reversing Iran’s nuclear program—and a timeline of diplomacy.

 

Iran’s Breaches

Tehran continued to comply with its obligations for more than a year after President Trump withdrew from the JCPOA. But in July 2019, it began breaching the agreement in response to Trump’s “maximum pressure” campaign. Iran’s breaches were incremental and calibrated until the assassination of Mohsen Fakhrizadeh, a top nuclear scientist, in November 2020.

Iran then took steps—including enriching uranium up to 20 percent—that could bring Tehran closer to sufficient fuel for a bomb. Enriching from 20 percent to weapons-grade levels—90 percent or higher—could be a relatively quick process if Tehran made the political decision to actually produce the world’s deadliest weapon.

Iranian officials have stressed that its nuclear advances are reversible. On April 2, 2021, Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, said that it could return to compliance within two to three months.

As a result of Iran’s breaches, the so-called breakout time – or the time Iran would need to enrich enough uranium to make one nuclear bomb – shortened from one year in 2015 to less than three months in 2021, the Institute for Science and International Security estimated. On April 11, 2011, an explosion destroyed the power supply and damaged or destroyed thousands of underground centrifuges used to enrich uranium at the Natanz nuclear facility. Iran vowed to replace the machines with more advanced models. David Albright, a physicist and former U.N. weapons inspector, warned that Iran could install enough advanced centrifuges to reduce the breakout timeline to around three months. The following is a timeline of Iran’s breaches.

July 1, 2019
Under the nuclear deal, Tehran was allowed to stockpile only 300 kilograms of low-enriched uranium. It was expected to sell or exchange any surplus. But on May 3, 2019, the United States vowed to sanction any country or company that helped Iran sell or exchange surplus, which left it with few alternatives to remain in compliance with the JCPOA. In retaliation, Tehran announced it would no longer honor the limit on its stockpile. On July 1, it accelerated the rate of production fourfold. 

The breach did not pose an immediate proliferation threat, according to the Arms Control Association’s Kelsey Davenport. Iran would need to produce at least 1,050 kilograms of highly-enriched uranium—nearly four times its stockpile at the time—to fuel a nuclear weapon. 

July 8, 2019
On July 8, Iran increased enrichment from 3.67 percent—a level suitable for fueling nuclear power reactors—to 4.5 percent. The slight breach, by itself, did not pose a short-term proliferation risk. Enrichment was still well below weapons-grade, which is more than 90 percent enriched uranium. It was also significantly lower than the 20 percent enrichment that Iran had reached in 2010, before the JCPOA in 2015. 

September 25, 2019
On September 25, Iran again breached the JCPOA by installing advanced centrifuges—20 IR-6s and 20 IR-4s—to enrich uranium at the Natanz facility near Isfahan. The IR-6 centrifuge can enrich uranium 10 times faster than the first-generation IR-1, according to Iranian officials. The JCPOA had limited Iran to using just over 5,000 IR-1s. Centrifuges cascade together to produce fissile material. A report by the International Atomic Energy Agency (IAEA) also verified that Iran had installed a cascade of 164 IR-4 and 164 IR-2m centrifuges. Iran’s third breach of the agreement was more significant than the previous two. It accelerated the production of fissile material and decreased the breakout time needed to develop a nuclear weapon.

November 7, 2019
On November 7, Iran injected uranium gas into 1,044 centrifuges at Fordo. The heavily fortified facility, built inside a mountain, was intended to be a research facility under the JCPOA, not an active site. The IR-1 centrifuges at Fordo had been spinning but were not enriching uranium. Salehi, Iran’s nuclear chief, specified that that the centrifuges would enrich uranium up to five percent at Fordo. 

November 16, 2019
On November 16, Iran informed the IAEA that its stock of heavy water exceeded the 130 metric ton limit under the JCPOA. On the following day, the watchdog confirmed that the Heavy Water Production Plant was active and that Iran had 131.5 metric tons of heavy water. Heavy water is often used as a moderator to slow down reactions in nuclear reactors. 

Heavy water reactors can also produce plutonium for use in nuclear weapons. But heavy water poses less of a proliferation concern than uranium because spent fuel from heavy water reactors must be reprocessed to separate the plutonium.  

January 5, 2020
On January 5, Iran announced its fifth step away from its commitments to the JCPOA. Tehran said it would not abide by restrictions on uranium enrichment capacity, percentage of enrichment, stockpile size of enriched material, and research and development.

September 4, 2020
The IAEA reported that Iran’s stockpile of low-enriched uranium reached 2,105 kilograms, or about 10 times more than the JCPOA limit. The stockpile had grown some 544 kilograms since the last quarterly report, released in June. Iran also began operating slightly more advanced centrifuges, but not enough shorten its breakout time, which remained three to four months. When Iran was in full compliance with the JCPOA, its breakout time had been 12 months. 

November 11, 2020
The IAEA reported that Iran's stockpile of low-enriched uranium reached 2,443 kilograms, or about 12 times more than the JCPOA limit. The stockpile had grown some 337.5 kilograms since the last quarterly report -- which indicated a slower rate of growth. But Iran also began using more advanced centrifuges at Natanz to enrich uranium. Iran's breakout time was approximately three months, the Institute for Science and International Security estimated.  

January 4, 2021
Iran resumed enriching uranium to 20 percent at the Fordo nuclear facility, a major breach of the 2015 nuclear deal. The JCPOA stipulated that Tehran could only enrich uranium to 3.67 percent. It also banned uranium enrichment at Fordo – a facility built deep inside a mountain to protect it from a military strike – until 2031.

Enriching uranium up to 20 percent brought Iran to where it was before the nuclear accord: on the cusp of acquiring sufficient fuel for a nuclear weapon. Uranium must be enriched to 90 percent or above to fuel a weapon, but enriching uranium gets easier the more highly concentrated it is. Enriching from 20 percent to 90 percent could be a relatively quick process, if Tehran made the political decision to do so. Enriching to 20 percent could shorten its breakout time even further.

January 13, 2021
Iran’s ambassador to the IAEA, Kazem Gharib Abadi, announced that Iran would produce uranium metal to help develop a new fuel for the Tehran civilian research reactor. But producing uranium metal was prohibited under the JCPOA because the material is necessary for making nuclear weapons. The metal can be used to cover the fuel rods that power a nuclear reaction. Iran said it would four to five months to install the necessary equipment to produce uranium powder, which could then made into metal. On January 14, the IAEA confirmed that Iran had reported that it had started installing the necessary equipment. 

February 10, 2021
The IAEA confirmed that Iran had enriched 3.6 grams of natural uranium metal. Under the deal, Iran was prohibited from manufacturing uranium or plutonium metals until 2030. Iran would need 500 grams of highly enriched uranium metal for a nuclear weapon core. The European parties to the deal had previously warned that there was "no credible civilian use" for the metals and that its production had "potentially grave military applications."

February 23, 2021
Iran suspended compliance with the Additional Protocol, a voluntary agreement that grants inspectors “snap” inspections and was part of the 2015 nuclear deal negotiated with the world’s six major powers. But Foreign Minister Mohammad Javad Zarif said that the step, and all other breaches of the deal, was "reversible" if the Biden administration lifted sanctions. 

March 15, 2021
The IAEA confirmed that Iran had begun enriching uranium at Natanz with IR-4 centrifuges. The IR-4 was the second type of advanced centrifuge, after the IR-2M, operating at the Natanz facility. The JCPOA had stipulated that Iran could only enrich at the facility with IR-1 centrifuges. 

April 10, 2021
Iran began testing its most advanced nuclear centrifuge, the IR-9, at the Natanz enrichment site. Under the nuclear deal, Iran could only operate 5,060 first-generation IR-1 centrifuges until 2025. The IR-9 can enrich uranium 50 times faster than the IR-1.

April 16, 2021
Iran began enriching uranium to 60 percent, the highest level of enrichment that it has publicly acknowledged. The move would be a major breach of the 2015 nuclear deal and brought Tehran closer to having weapons grade uranium. Iran also planned to install 1,000 additional centrifuges at Natanz.

The breach coincided with the resumption of indirect talks between the United States and Iran in Vienna over returning to the JCPOA. Britain, France and Germany called the move was "dangerous" and "contrary to the constructive spirit and good faith of these discussions." Secretary of State Antony Blinken said that the decision to enrich up to 60 percent "provocative" and that it "calls into question Iran's seriousness" at the talks.

President Rouhani reiterated that Iran was not seeking a nuclear weapon. “We can enrich to 90 percent today, but we stand by our word and we are not looking for an atomic bomb,” he said on April 15 during a cabinet meeting. “It is YOU who made and stockpiled the atomic bomb and are still making bombs. This is what YOU do. Do not accuse us of making bombs, Iran's activities are completely peaceful.”

 

U.S. Sanctions

The most complicated issue in U.S.-Iran diplomacy is the overlapping network of U.S. sanctions that punish the Islamic Republic on multiple counts, from activities related to the nuclear program and support of terrorism to missile proliferation and human rights abuses. Some of Iran’s major institutions, including the Central Bank and the National Iranian Oil Company (NIOC), are sanctioned both for their roles supporting the nuclear program and for aiding terrorist attacks by proxy militias.

The Biden administration has vowed to lift the sanctions related to Iran’s nuclear program – as promised in the 2015 deal – if Tehran, in turn, rolls back recent breaches of the nuclear deal. The complicating factor in current and future diplomacy is that key Iranian institutions and individuals could remain sanctioned for secondary reasons, thus not providing Iran the economic relief it seeks. On April 7, State Department Spokesperson Ned Price said that the United States was prepared to lift sanctions that are “inconsistent with the JCPOA” but did not provide further details.

The issue of sanctions was complicated when President Donald Trump abandoned the nuclear deal—brokered by the world’s six major powers over two years of intense diplomacy—in 2018. He then reimposed earlier sanctions from the Bush and Obama administrations that had been lifted when the Joint Comprehensive Plan of Action (JCPOA) was implemented in 2016. He also took the unusual step of sanctioning Iran’s banking and oil sectors for funding the Revolutionary Guards and extremist proxies across the Middle East. The Trump administration imposed sanctions on more than 1,500 individuals and entities.

The Iranian delegation to the April 2021 talks included representatives from the Central Bank of Iran and the Petroleum Ministry, which reflected Tehran’s interest in sanctions relief. The following is a list of major banking, shipping and oil institutions sanctioned by the Trump administration under multiple authorities.

Central Bank of Iran 

The Central Bank, established in 1960, is the primary conduit for oil sales transactions, a key source of Iran’s foreign exchange. But since 2018, U.S. sanctions have made it hard for Iran to sell its oil abroad and be paid in hard currency because the bank was cut from the international financial system. The bank has been unable to repatriate tens of billions of dollars in frozen assets in foreign banks due to U.S. sanctions. The following is a timeline of U.S. sanctions on the Central Bank:      

• In February 2012, the Obama administration sanctioned all Iranian financial institutions, including the Central Bank, to pressure Tehran to negotiate limits on its nuclear program.

• In January 2016, sanctions on the Central Bank were lifted as part of the JCPOA.

• In May 2018, Trump abandoned the JCPOA.

• In November 2018, five months after withdrawing from the JCPOA, the Trump administration reimposed sanctions on the Central Bank.

• In September 2019, the Trump administration sanctioned the bank for facilitating funding for Iran’s links to terrorism. 

 

National Iranian Oil Company

Established in 1951 after Iran nationalized its oil industry, the National Iranian Oil Company (NIOC) is responsible for exporting oil and gas as well as exploration, drilling, production and research and development. It is overseen by the Ministry of Petroleum. NIOC was the ninth-largest state-owned oil company in the world, based on 2019 revenues. Iran has fourth-largest oil reserves and the second-largest gas reserves in the world. The following is a timeline of sanctions on NIOC:

• In November 2012, the Obama administration sanctioned NIOC for weapons of mass destruction proliferation by providing financial, material or other support to the Islamic Revolutionary Guard Corps (IRGC). 

• In January 2016, sanctions on NIOC were lifted as one of the incentives for Iran to agree to limits on its nuclear program and as part of the JCPOA. 

• In May 2018, Trump abandoned the JCPOA.

• In November 2018, five months after withdrawing from the JCPOA, the Trump administration reimposed sanctions on NIOC.

• In October 2020, the Trump administration sanctioned NIOC for facilitating terrorism through financial support to the IRGC, especially its external operations arm, the Qods Force.

 

National Petrochemical Company

Established in 1964, the National Petrochemical Company (NPC) is a subsidiary of the Ministry of Petroleum. Petrochemical exports, including chemicals, fertilizers, fuel and polymers, are the second-largest source of government revenue after crude oil. As of early 2021, petrochemical exports accounted for nearly a third of non-oil exports. The NPC has historically been the second largest producer and exporter of petrochemicals in the Middle East, after Saudi Arabia. The following is a timeline of sanctions on the NPC:

• In June 2010, the Obama administration sanctioned the NPC to pressure Tehran to curb its nuclear and missile programs. The NPC was among 22 companies determined to be owned or controlled by the Iranian government.

• In January 2016, sanctions on the NPC were lifted as one of the incentives for Iran to agree to limits on its nuclear program and as part of the JCPOA.

• In May 2018, Trump abandoned the JCPOA.

• In November 2018, five months after withdrawing from the JCPOA, the Trump administration reimposed sanctions on the NPC.

• In October 2020, the Trump administration sanctioned the NPC for facilitating terrorism by being controlled by the Ministry of Petroleum, which generated revenue for the IRGC.

 

National Iranian Tanker Company

Established in 1955, the National Iranian Tanker Company (NITC) transports Iranian crude oil for export and stockpiles oil in floating storage units. It is a subsidiary of the NIOC. As of 2019, NITC had a fleet of at least 54 tankers, including 38 Very Large Crude Carriers and eight Suezmaxes. NITC tankers began shipping millions of barrels of oil to Venezuela starting in May 2019. The following is a timeline of sanctions on NITC:

• In July 2012, the Obama administration sanctioned NITC, 58 vessels and 27 affiliates under helping Iran evade sanctions.

• In January 2016, sanctions on NITC were lifted as one of the incentives for Iran to agree to limits on its nuclear program and as part of the JCPOA.

• In May 2018, Trump abandoned the JCPOA.

• In November 2018, five months after withdrawing from the JCPOA, the Trump administration reimposed sanctions on NITC.

• In June 2020, the Treasury sanctioned captains working for NITC for shipping gasoline to Venezuela.

• In October 2020, the Treasury sanctioned NITC for facilitating funding for Iran’s links to terrorism. It accused NITC personnel of coordinating with Hezbollah on logistics and pricings for oil shipments to Syria.

 

Islamic Republic of Iran Shipping Lines

Established in 1967, the Islamic Republic of Iran Shipping Lines (IRISL) is the national shipping company. It started under the name Aria Shipping Lines with six vessels. As of 2019, it operated a fleet of 115 vessels but many were old and unsafe for travel. IRISL has dozens of affiliates it uses to evade U.S. and international sanctions. The company has falsified documents to conceal military-related shipments from maritime authorities. The following is a timeline of sanctions on IRISL:

• In September 2008, the George W. Bush administration sanctioned IRISL and 18 affiliates for shipping cargo used in Iran’s proliferation of weapons of mass destruction. In 2010, the Obama administration sanctioned dozens more IRISL affiliates as part of sanctions on Iran’s nuclear and missile programs.

• In January 2016, sanctions on IRISL and its affiliates were lifted as one of the incentives for Iran to agree to limits on its nuclear program as part of the JCPOA.

• In May 2018, Trump abandoned the JCPOA.

• In November 2018, five months after withdrawing from the JCPOA, the Trump administration reimposed sanctions on IRISL and its affiliates.

• In September 2019, the Treasury sanctioned an “oil-for-terror” shipping network that included IRISL-linked vessels.

• In December 2019, the State Department designated IRISL for transporting material used in Iran’s missile program. The designations took effect after 180 days to allow Iran to find alternative ways to ship humanitarian supplies.

• In June 2020, the Treasury sanctioned captains working for IRISL for shipping gasoline to Venezuela.

 

Private banks

In November 2018, the Trump administration reimposed punitive economic sanctions on most major public and private Iranian banks. Many private banks had been sanctioned by previous administrations for money laundering and sanctions evasion. U.S. sanctions cut them off from the global financial system. The difference between public and private banks in complicated in Iran because many private banks are owned by official or military organizations, while other banks are reportedly controlled by private conglomerates or charitable foundations (bonyads) that are also linked to the government.

Between 2018 and 2020, the Treasury took the additional – and unusual – step of sanctioning banks for facilitating funding for terrorism; it cited malign activities by the Revolutionary Guards and proxy militias across the Middle East. In 2020, President Trump’s Executive Order 13902 further authorized the Treasury to sanction any Iranian financial institution. U.S. sanctions were intended to have a chilling effect on foreign transactions with Iran. The following is the timeline of U.S. sanctions on private banks: 

• In February 2012, the Obama administration froze the assets of all Iranian financial institutions held in the United States to pressure Tehran to negotiate limits on its nuclear program.

• In January 2016, the Obama administration lifted sanctions on dozens of Iranian banks as part of the Iran nuclear deal.

• In May 2018, Trump abandoned the JCPOA.

• In October 2018, the Treasury sanctioned several banks—including Bank Mellat, Parsian Bank, Sina Bank and Mehr Eqtesad Bank--for supporting the Basij under its counterterrorism authorities. Mehr Eqtesad had not previously been sanctioned.

• In November 2018, the Trump administration reimposed sanctions on 50 Iranian banks and their subsidiaries, including Amin Investment Bank, Arian Bank, Ayandeh Bank, Bank Kargoshaee, Bank Maskan, Bank Melli, Bank Sepah, Bank Tejarat, Day Bank and Future Bank.

• In October 2020, the Treasury sanctioned 18 major banks to deny Iran funding for its nuclear program, missile development or support for terrorism. The sanctioned banks included Amin Investment Bank, Bank Keshavarzi Iran, Bank Maskan, Bank Refah Kargaran, Bank-e Shahr, Eghtesad Novin Bank, Gharzolhasaneh Resalat Bank, Hekmat Iranian Bank, Iran Zamin Bank, Islamic Regional Cooperation Bank, Karafarin Bank, Khavarmianeh Bank (also known as Middle East Bank), Mehr Iran Credit Union Bank, Pasargad Bank, Saman Bank, Sarmayeh Bank, Tosee Taavon Bank (also known as Cooperative Development Bank), and Tourism Bank.

 

Timeline of Vienna Talks

April 6, 2021: Indirect talks between the United States and Iran began in Vienna. Two expert working groups were formed: one on the timetable for lifting U.S. sanctions on Iran, the other on reversing Iran's breaches of the nuclear deal. Aragchi said that negotiations were on "the right track," but that it was "too soon to say it has been successful."

April 7, 2021: Special Envoy Malley met with Mikhail Ulyanov, the Russian ambassador in Vienna. "We had a businesslike discussion on issues related to restoration of full implementation of the #JCPOA by all sides," Ulyanov tweeted. Malley also met with IAEA Director General Rafael Grossi. 

April 8, 2021: Deputy Foreign Minister Abbas Araghchi met with IAEA Director General Grossi while in Vienna. Araghchi said that the IAEA would play an "important role" in verification if Iran came to an agreement with the world powers over returning to compliance with the JCPOA. 

April 9, 2021: The first week of talks in Vienna concluded. No final agreement was reached, but participants agreed to reconvene the following week. The P4+1 "took stock of the work done by experts over the last three days and noted with satisfaction the initial progress made," Ambassador Ulyanov tweeted. 

April 11, 2021: An explosion at Natanz hit the power supply for centrifuges and caused damage that could take up to nine months to fully repair, The New York Times reported. "Thousands of centrifuges" were destroyed, according to Alireza Zakani, head of Iran's Parliament Research Center. Foreign Minister Zarif blamed Israel but insisted that Iran would not "allow this act of sabotage to affect the nuclear talks.”

April 13, 2021: Iran said that it will begin enriching uranium to 60 percent, the highest level of enrichment that it has publicly acknowledged. The move would be a major breach of the 2015 nuclear deal and brought Tehran closer to having weapons grade uranium. Iran also planned to install 1,000 additional centrifuges at Natanz. 

April 14, 2021: Britain, France and Germany expressed "grave concern" about Iran's decision to enrich uranium up to 60 percent. "Iran has no credible civilian need for enrichment at this level," the three European countries said in a joint statement. They condemned the move as "contrary to the constructive spirit and good faith" of diplomatic negotiations. Secretary of State Blinken called the decision to enrich up to 60 percent "provocative" and that it "calls into question Iran's seriousness" at the Vienna talks. "We're committed to pursuing that process, but the real question is whether Iran is," he said in Brussels.

April 15, 2021: Indirect talks over getting the United State and Iran back into compliance with the JCPOA resumed in Vienna. In Tehran, President Rouhani reiterated that Iran was not seeking a nuclear weapon. “We can enrich 90 percent today, but we stand by our word and we are not looking for an atomic bomb,” he said during a cabinet meeting. “It is YOU who made and stockpiled the atomic bomb and are still making bombs. This is what YOU do. Do not accuse us of making bombs, Iran's activities are completely peaceful.”

April 16, 2021: Iran began enriching uranium up to 60 percent. “We are producing about nine grams of 60 percent enriched uranium an hour,” AEOI chief Salehi said. President Joe Biden said that the step was not "helpful" to negotiations in Vienna. "We are, though, nonetheless, pleased that Iran has continued to agree to engage in discussions, indirect discussions with us and with our partners on how we move forward," he said at a news conference in the Rose Garden. The heads of the Chinese, Russian and Iranian delegations held a trilateral meeting. 

April 17, 2021: The Joint Commission instructed the expert-level working groups to work over the weekend. "We need now more detailed work," Enrique Mora, E.U. coordinator for the talks tweeted. "Key that everyone is committed to the same objectives"

April 19, 2021: The U.S. and Russian delegations in Vienna held "useful" bilateral talks on lifting U.S. sanctions and returning Iran to full compliance with the JCPOA, Ambassador Ulyanov tweeted. 

April 20, 2021: The Joint Commission created a third expert group "to start looking into the possible sequencing of respective measures" by the United States and Iran to reenter the JCPOA. Diplomatic talks in Vienna paused to give delegations time to consult with their capitals. Parties would resume discussions the following week. "There has been some progress, but there remains a long road ahead," State Department spokesperson Ned Price said. "And I think it’s fair to say that we have more road ahead of us than we do in the rearview mirror."

 

Photo Credits: Central Bank Building by GTVM92 via Wikimedia Commons (CC-BY-SA-4.0); NIOC building by GTVM92 via Wikimedia Commons (CC-BY-SA-4.0); IRISL containers by IDF via Wikimedia Commons (CC-BY-SA-2.0)