The Presidential Candidates on the Iran Nuclear Deal
from Candidates Answer CFR's Questions

The Presidential Candidates on the Iran Nuclear Deal

July 30, 2019 11:49 am (EST)

Current political and economic issues succinctly explained.

More on:

Elections and Voting

Election 2020

CFR invited the presidential candidates challenging President Trump in the 2020 election to articulate their positions on twelve critical foreign policy issues. Candidates’ answers are posted exactly as they are received. View all questions here.


More From Our Experts

Would you rejoin the 2015 Joint Comprehensive Plan of Action (JCPOA)? What changes to the existing agreement, if any, would you require before agreeing to rejoin the accord?

Joe Biden

Joe Biden Former vice president of the United States

Iran is a destabilizing actor in the Middle East; it must never be allowed to develop a nuclear weapon. President Trump abandoned the Joint Comprehensive Plan of Action (JCPOA)—a deal that blocked Iran’s paths to nuclear weapons, as repeatedly verified by international inspectors—with no viable plan to produce a better one. His reckless actions have produced a deep crisis in transatlantic relations and pushed China and Russia closer to Iran. As a result, the United States, rather than Iran, has been isolated. Predictably, Iran has restarted its nuclear program and become more aggressive, moving the region closer to another disastrous war. In short, Trump’s decisions have left us much worse off.

What Iran is doing is dangerous, but still reversible. If Iran moves back into compliance with its nuclear obligations, I would re-enter the JCPOA as a starting point to work alongside our allies in Europe and other world powers to extend the deal’s nuclear constraints. Doing so would provide a critical down payment to re-establish U.S. credibility, signaling to the world that America’s word and international commitments once again mean something. I would also leverage renewed international consensus around America’s Iran policy—and a redoubled commitment to diplomacy—to more effectively push back against Tehran’s other malign behavior in the region.

Read all of Joe Biden’s responses.

More From Our Experts


Michael Bloomberg

Michael Bloomberg Former mayor of New York City Withdrawn

The United States will not allow Iran to develop or acquire nuclear weapons. I was initially against the Iran deal, but it was a mistake for President Trump to unilaterally walk away from it. While the agreement was not perfect — it did not address Iran’s ballistic-missile program, and it gave the regime political cover to step up its aggression in the region — the U.S. had an obligation to keep its word once the agreement was in place. The U.S. withdrawal has allowed Iran to abandon its own obligations under the deal, and has left the world with few tools to stop it. 

The first thing to do is reestablish the coalition that realized the danger of Iran marching toward a nuclear weapon. Collective pressure will be needed to change Iran’s behavior. This should be the starting point for the use of diplomacy. We should also be prepared to employ the leverage that sanctions have provided. 

Next, Iran must come back into compliance with the JCPOA requirements. That will require addressing the advances it is likely to make between now and next year—advances that could shrink its breakout time. After rejoining, in order for any new arrangement to be sustainable, we must also be ready to address other inadequacies in the deal, which include the need to extend fast-approaching sunset clauses, curtail Iran’s ballistic missiles, end its destabilizing regional activities and institute more intrusive monitoring. 

Read all of Michael Bloomberg’s responses.

Cory Booker

Cory Booker Senator, New JerseyWithdrawn

It was a serious mistake for President Trump to withdraw from the Iran nuclear deal, and I never would have done it. The JCPOA brought transparency into Iran’s nuclear program and pushed back a nuclear breakout by at least 10 years. Without an agreement, Iran is now able to rapidly enrich uranium and drastically reduce the time it would take for them to produce a nuclear weapon.

While I strongly support a nuclear deal with Iran, we cannot turn back the clock and pretend the damage that President Trump has caused over the last 3 years hasn’t happened. The 2015 deal was premised on continued negotiations with the Iranians so that we could work towards a longer-term solution. We will have had four years wasted under Trump, and the sunset clauses, after which key provisions will phase out, are now that much closer. We must take stock of facts on the ground, including Iran’s recent breach of its enrichment limit, and negotiate an updated agreement to stop the threat posed by Iran’s nuclear program.

Read all of Cory Booker’s responses.

Steve Bullock

Steve Bullock Governor of Montana Withdrawn

Yes. I would rejoin the JCPOA, if it is still an option by January 2021. A nuclear Iran would further destabilize the entire Middle East and we must prevent it. I would work closely with our European allies and collaborate towards our common goal of a non-nuclear Iran and a Middle East that can work toward peace and prosperity without the constant threat of nuclear conflict.

Read all of Steve Bullock’s responses.

Pete Buttigieg

Pete Buttigieg Former mayor of South Bend, Indiana Withdrawn

I have been clear: walking away from the JCPOA was a strategic mistake. We didn’t develop the deal as a favor to Iran; we did it because it was in our national security interest. The deal represented a detailed and verifiable arrangement that permanently prohibited Iran from acquiring a nuclear weapon. And the JCPOA was effective: Iran was upholding its commitments, as confirmed repeatedly by international inspectors and our own intelligence community, when President Trump withdrew from it. Walking away from the JCPOA also cost us credibility and the trust of our partners, hindering our ability to work with allies to solve difficult collective challenges. 

We should have no illusions about the reality that Iran poses challenges to U.S. interests beyond its nuclear program: its ballistic missile program, malign behavior in the region, threats to our ally Israel, and human rights abuses. But having the JCPOA in place created a foundation from which we could begin addressing those concerns, all of which will be even more intractable if we lack a mechanism to verifiably and permanently prevent Iran from acquiring a nuclear weapon. 

If Iran resumes implementing its commitments, then I would rejoin. But I would take the agreement as a floor, not a ceiling. I would revive P5+1 diplomacy and direct US-Iran dialogue at the appropriate levels and would want to pursue follow-on agreements that extend the timeframe of certain nuclear restrictions, cover Iran’s missile program, and address its role in regional conflicts, all in return for targeted sanctions relief. 

Read all of Pete Buttigieg’s responses.

Julian Castro

Julian Castro Former secretary of housing and urban developmentWithdrawn

The Iran nuclear deal is the best way to prevent Iran from obtaining a nuclear weapon and prevent conflict in the Middle East. President Trump’s decision to pull out of the JCPOA not only isolated us from our closest allies, it needlessly escalated tensions with Iran and has increased the risk of conflict. I would rejoin the JCPOA, provided that Iran is verifiably in compliance with the deal that President Obama and our European allies negotiated. 

With the JCPOA firmly in place and Iran restrained from developing nuclear weapons, I will work with our allies to address other troubling aspects of Iranian behavior, including Iran’s ballistic missile program, its human rights record, and its destabilizing actions in the region.

Read all of Julian Castro’s responses.

John Delaney

John Delaney Former representative, MarylandWithdrawn

Yes, I would rejoin, but I would insist on a longer duration. The JCPOA was the best arrangement that six of the leading nations in the world, plus the European Union, could reach to prevent Iran from developing nuclear weapons. At the time the Trump Administration withdrew from the JCPOA, Iran was in compliance with the terms. U.S. withdrawal has become a provocation for the Iranians to not feel constrained to abide by the JCPOA, which has made the situation with Iran inherently more dangerous. The most significant weakness of the JCPOA was the tenor- it was not long enough in duration to provide hope for a successor Iranian regime to confirm long-term compliance. I would seek a longer term - 20 years - as a condition for rejoining the JCPOA. In addition, I would make clear to the Iranians that, while the JCPOA does not address Iranian ICBM developments or Iranian complicity in terrorist activities, the United States will independently of the nuclear deal take strong measures to respond to any such conduct. Iran is a bad actor, and the JCPOA with a longer duration is an important part of eliminating the threat that Iran can possess a nuclear weapon, a situation that must not be accepted.

Read all of John Delaney’s responses.

Kirsten Gillibrand

Kirsten Gillibrand Senator, New York Withdrawn

Abandoning the Iran nuclear deal was reckless and dangerous. We need to rejoin our allies in returning to the agreement, provided Iran agrees to comply with the agreement and take steps to reverse its breaches, and strengthen the deal. While President Trump’s reckless policies have moved American security and the security of allies backwards, I would - together with our allies - press Iran to extend the agreement for a longer period, and tackle other security issues from Iran’s missile program to its support for terrorists. I believe that our leverage will increase if Iran sees the benefit of agreeing to a deal.

Read all of Kirsten Gillibrand’s responses.

Kamala Harris

Kamala Harris Senator, California Withdrawn

Yes. President Trump’s unilateral withdrawal from an agreement that was verifiably preventing Iran from obtaining a nuclear weapon – against the warnings of our closest allies, and without any plan for what comes next – was beyond reckless. Since then, we’ve seen nothing but escalations from both sides. Either the Trump Administration is angling for another disastrous war in the Middle East, or it has spent two years saber-rattling with no endgame.
Based on where things stand now, I would plan to rejoin the JCPOA so long as Iran also returned to verifiable compliance. At the same time, I would seek negotiations with Iran to extend and supplement some of the nuclear deal’s existing provisions, and work with our partners to counter Iran’s destabilizing behavior in the region, including with regard to its ballistic missile program.

Read all of Kamala Harris's responses.

Seth Moulton

Seth Moulton Representative, Massachusetts Withdrawn

Yes. The best and most durable way to prevent Iran from becoming a nuclear-armed state is to do so through a diplomatic agreement with verification and monitoring, which we had in place before President Trump unilaterally withdrew from it. Therefore, our first goal should be rejoining the Iran deal and strengthening it, focused on extending the timelines for the specific provisions that have sunset clauses. We should also work to conclude separate agreements addressing issues such as ballistic missiles. The secondary, longer-term goal should be to move Iran towards less belligerent behavior in the region, where Iran is not threatening our allies or our interests. Neither of these goals can be achieved by simply backing Iran into a corner with no escape. We need to use sanctions, open a direct dialogue with Iran, and give them a path forward that does not include outright war.

Read all of Seth Moulton’s responses.

Beto O’Rourke

Beto O’Rourke Former representative, TexasWithdrawn

Yes, as President, I will rejoin the JCPOA, conditioned on Iran’s compliance with its commitments under the agreement. President Trump’s decision to withdraw from the JCPOA was short-sighted, reckless, and against the recommendations of both the U.S. and Israeli intelligence communities. The nuclear agreement was not perfect—no negotiated agreement can be—but it significantly advanced American interests and was succeeding in blocking Iran’s pathway to achieving nuclear capability. Moreover, our sudden withdrawal has made the United States and our allies less safe and weakened our credibility as a good-faith negotiator for subsequent dealings with Iran and other regimes. 

As President, I will reverse these policies. I will restore US credibility, and use the agreement as a starting point for future negotiations, along with our allies, aimed at reigning in Iran’s most destabilizing behavior in the region, limiting Iran’s ballistic missile capability, and ensuring that Iran never becomes a nuclear weapon state. 

President Trump’s reckless and cavalier saber-rattling is moving us closer to a military confrontation with the Iranian regime. As President, I will put an end to this irresponsible approach. I will work with our allies in Europe and in the region to tackle the serious challenges posed by the Iranian regime and restore our commitment to the hard work of diplomacy.

Read all of Beto O'Rourke responses.

Deval Patrick

Deval Patrick Former governor, Massachusetts Withdrawn

The present regime in control of Iran is a threat to the security of Israel, the region, and beyond.  Iran’s nuclear capability must be checked.  The right way to do so is as part of a coalition with our allies and others in the region and beyond. 

The JCPOA was an impressive achievement that should have remained in place.  It could have been—and should still be—strengthened in some respects, such as extending the agreement to cover development of ballistic missiles and permitting more intrusive inspections.  

The JCPOA promised tangible progress that improved U.S. national and regional security while opening the door to relief for the Iranian people through continued negotiations. Withdrawing from it without an alternative in place has worsened the conditions for regional and national security.  The new solution must reflect the changed reality, which might require amendments to the original terms of the JCPOA.  We will again work with our global allies to solve this urgent problem.

Our relationship with Iran should be viewed as being part of a comprehensive regional plan for peace and prosperity in the Middle East.  Such a strategy involves defending Israel, countering violent extremism, and promoting economic development.  We will work with partners in Iraq and beyond to mend the Sunni-Shia rift.  We must also counter the threat of a nuclear Iran and, through diplomacy, ease rivalries around the Gulf. We will rebuild strategic alliances to win back the ground we have lost against regional adversaries, including ISIS, after President Trump’s damaging decision to withdraw from Syria.  My administration will also work with Congress to pursue a regional development package to strengthen cross-border ties through new, incentive-driven investment in technology, energy and infrastructure.

Read all of Deval Patrick’s responses.

Tim Ryan Representative, Ohio Withdrawn

At this point, it would be impossible to rejoin the JCPOA as it was written in 2015. I would absolutely support entering a new version of the JCPOA that extends restrictions even further into the future, but I would not compensate the Iranians for economic losses suffered after the U.S. left the agreement. It is in Iran’s interest to reenter the agreement in order to lift sanctions, they do not need to be compensated beyond that, especially given the possibility that this money could end up in the hands of terrorist organizations and malicious actors throughout the region.

Read all of Tim Ryan’s responses.

Bernie Sanders

Bernie Sanders Senator, Vermont Withdrawn

Yes. The agreement achieved by the US, Europe, Russia and China with Iran is one of the strongest anti-nuclear agreements ever negotiated. It prevented a war and blocked Iran’s path to a nuclear weapon. I would re-enter the agreement on day one of my presidency and then work with the P5+1 and Iran to build upon it with additional measures to further block any path to a nuclear weapon, restrain Iran’s offensive actions in the region and forge a new strategic balance in the Middle East.

Read all of Bernie Sanders’s responses.

Joe Sestak

Joe Sestak Former representative, PennsylvaniaWithdrawn

I would move to rejoin the Iran nuclear deal (JCPOA) as soon as possible upon my swearing in. We never should have left it in the first place. We broke our word, so we should not be demanding changes to the agreement, but rather recognize the value of the nuclear accord as is. Certainly, the JCPOA was not a perfect agreement. It did not deal with the threat from Iranian missiles, or their support for violent extremism. And it contains a “sunset clause,” meaning it  expires after a decade. But it was accomplishing the one goal it set out to achieve: stopping Iran from developing nuclear weapons. On that metric alone, it was a success. International disarmament agreements are complicated, and it’s normal for them to sunset after a given period of time. In this case, the deal was good enough to be supported by all of our European allies, along with Russia and China, and of course Iran itself. Iran was abiding by its terms. If the deal had been given the chance to hold for the full decade, it would have created a reservoir of goodwill between Iran and the world that would be the basis for the next agreement. After decades of animosity between Iran and the United States, it takes time to build trust. The JCPOA was doing that. Our leaving the agreement not only destroyed a carefully crafted international agreement, it also sapped our credibility in negotiations with other countries, like North Korea. 

What’s worse, our Iran policy now seems to dismiss the principle that “militaries can stop a problem, but militaries cannot fix a problem.” Our diplomacy had convened the world and reached agreement on economic sanctions, including with new bedfellows such as Russia and China. Now our military is poised to “stop” a problem we had already “fixed” by diplomacy. Even if this were to occur, such as with strikes to destroy their nuclear infrastructure, at most, such strikes would result in delaying Iran’s timetable for creating a nuclear weapon by only four years. The results would also include fractured alliances, economic disarray, more nuclear arms races, and a loss of U.S. credibility and leadership within our rules-based world order – requiring fixing.

Read all of Joe Sestak’s responses.

Elizabeth Warren

Elizabeth Warren Senator, Massachusetts Withdrawn

If Iran returns to compliance with its obligations under the nuclear deal, the United States should return as well. If Iran is not in compliance, I will pursue strong and principled diplomacy in concert with our allies to bring both the United States and Iran back into the deal.

The JCPOA is only the beginning. We will need to negotiate a follow-on to the agreement that continues to constrain Iran’s nuclear program past the “sunset” of some of its original terms. 

We also need to address serious concerns about Iran’s policies beyond its nuclear program, including its ballistic missile program and support for destabilizing regional proxies. The JCPOA made addressing these problems easier by taking the threat of a nuclear-armed Iran off the table. As predicted, President Trump’s reckless decision to withdraw from the agreement has clearly put us in a weaker position, and to make progress we will need to rebuild support from regional and international actors whose interests are also at stake. But with time and leverage, the damage can be undone and diplomacy can be successful again. 

Read all of Elizabeth Warren’s responses.

Bill Weld

Bill Weld Former governor, MassachusettsWithdrawn

I thought that Mr. Trump’s withdrawal from the 2015 JCPOA was a colossal blunder. We had a ten-year period during which Iran would not advance its nuclear weapons program, and they were in compliance. I would rejoin the JCPOA without changes to the written agreement.

Read all of Bill Weld’s responses.

Marianne Williamson

Marianne Williamson AuthorWithdrawn

I would rejoin the JCPOA, a historic achievement in multilateral diplomacy. Every IAEA report confirmed Iran's compliance. US withdrawal and severe sanctions violated the trust that had been painstakingly built. Rejoining the JCPOA will require healing from this rupture and rebuilding trust. 

After the deal, Iranian moderates gained popularity and fundamentalists lost power. President Rouhani was elected to restore the economy and improve relationships with the West. Foreign Minister Zarif, who led negotiations, had a good relationship with then Secretary Kerry. This deal was intended as a first step toward improving relationships. 

The Supreme Leader and hardliners opposed the deal. US withdrawal increases their popularity and justifies their mistrust of the US. Our sanctions are harming the Iranian people. 

US propaganda exaggerates threats, and falsely claims the deal lets Iran get nuclear weapons within 10 years. This disregards the likelihood of changed dynamics and improved relationships. Iran is a potential ally against Sunni extremism with many common interests to build upon. 

Over half of Iran’s graduate students are women. About 60% of the people are under 30. Many of them want normal relations with the West. 

Iran is a political football. The UAE and Saudi Arabia do not want the US to improve relations with Iran and would like to provoke a war. It is said that the Saudis want to fight Iranians to the last American. We need to be careful to not be drawn into war by those who want us to fight Iranians for them. I would increase diplomacy, decrease tensions, and transform relations to create a context to address human rights and other issues. Sanctions relief and purchasing Air Buses would support travel, entrepreneurship and normalization.

Read all of Marianne Williamson’s responses.

Andrew Yang

Andrew Yang Entrepreneur Withdrawn

Iran is a destabilizing force in the region, and the JCPOA gave us both short-term victories in stabilizing the region through minimizing their influence, and inroads to further discussion to find a solution that would work over a longer period. Leaving the JCPOA was a massive strategic mistake, and one that only served to increase the likelihood of armed conflict in the country. The American people have no desire for armed conflict with Iran, which would lead to another multi-decade engagement that would spread throughout the region and have no clear benefit for the American people.

We need to work with our allies that are still party to the agreement to negotiate a new JCPOA, with longer terms and delayed deadlines to reflect the time wasted with Trump and Bolton’s posturing. We need to get Iran back in compliance with the limitations placed on them under the agreement on nuclear materials and enrichment capabilities.

Then, we need to build on the agreement to get Iran to stop destabilizing the region, attacking our allies, funding terrorist organizations, and causing conflict in the Strait of Hormuz.

Read all of Andrew Yang’s responses.


This project was made possible in part by a grant from Carnegie Corporation of New York.


    More on:

    Elections and Voting

    Election 2020

    Creative Commons
    Creative Commons: Some rights reserved.
    This work is licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) License.
    View License Detail

    Top Stories on CFR

    NATO (North Atlantic Treaty Organization)

    The war in Ukraine marks a new era of instability in Europe. Countering Russia’s efforts will require a stronger, more coordinated NATO.


    After the rise of Chinese power during the 2010s and failed U.S. policies in the Indo-Pacific, the United States should renew the Pivot to Asia and place the region at the center of its grand strategy.*


    Far-right advances in the European Parliament elections have destabilized politics in France, a longstanding pillar of the European Union, and highlighted fault lines in the bloc.