Two experts in nuclear proliferation and an attentive audience discussed if Iran can be stopped from getting a nuclear bomb on Thursday. But the two experts, Senior Fellow at the Brookings Institute Robert Einhorn and Senior Executive Director of the Crown Center for Middle East Studies Gary Samore (POL), disagreed on the likelihood of Iran eventually developing nuclear weapons.

Einhorn is a senior fellow at the Brookings Institute who worked under the Clinton and Obama administrations, helped to lead U.S. efforts to constrain North Korea’s missile program and was a part of the direct negotiations with Iran that led to the Joint Comprehensive Plan of Action (JCPOA), more commonly known as the Iran deal.

Einhorn and Samore discussed the JCPOA. Samore also has extensive experience in nuclear proliferation, working in both the Clinton and Obama administrations on the topic.

The JCPOA, which Einhorn called, “the best [deal] that could be achieved at the time,” was an agreement that limited Iran’s ability to create nuclear weapons for the next 10 to 15 years in exchange for economic sanctions relief from the United States. President Donald Trump pulled the U.S. out of the JCPOA and reimposed economic sanctions, causing heavy economic burdens on Iran and the perception that the U.S. wants Iran to either “capitulate or to collapse,” according to Einhorn.

The title of the talk, “Can Iran be stopped from getting the bomb,” was answered differently by Samore and Einhorn. Einhorn didn’t believe that Iran would inevitably get nuclear weapons, saying, “I think they [Iran] have genuinely not made up their mind yet.”

But Samore thought differently. “Bob (Einhorn) says the final decision hasn’t been made,” Samore said. “I think, with the current crop of leaders, the temptation to build nuclear weapons—if they think they can get away with it and if they have the technical capacity—it’s going to be too hard to resist.”

Einhorn and Samore discussed the history of the Iranian nuclear program, which included nuclear energy and a covert program to develop nuclear weapons with enriched Uranium, an element that can be used for nuclear energy or weapons development depending on the level of enrichment. When the Iranian nuclear weapons program was discovered in 2003, the discovery set of a chain of diplomatic talks, temporary agreements and negotiations, eventually resulting in the JCPOA.

But Iran didn’t give up on their nuclear ambitions. “Through all the twists and turns they’ve been able to creep closer and closer to nuclear weapons technology,” Samore said.

The two experts also discussed criticisms of the JCPOA that contributed to Trump pulling out of the deal. Critics argue that the JCPOA only stalls Iranian nuclear weapons development, and doesn’t address other issues between Iran and the United States, such as Iranian support for terrorist organizations like Hezbollah.

But Einhorn disagreed, saying an “all or nothing” deal would hold a nuclear deal hostage to other issues that were less important to national security.

Einhorn also recommended that, though pulling out of the JCPOA was a poor decision, a potential democratic president in 2020 should do more than just rejoin the original deal.

“If I were advising the democrats I would say don’t go right back to the JCPOA,” he said. “In doing that you’re giving up the leverage that the Trump administration has provided in terms of the sanctions, but I would enforce those sanctions in a kind of kinder, gentler way.” Einhorn also recommended that the U.S. be willing to relax primary U.S. sanctions in exchange for further Iranian concessions.

Einhorn encouraged mending relations with key states. “We’re not going to get the Iranians back to the negotiating table unless we have the support of these key partner governments,” he said, identifying Russia and China as key to the negotiations.

Einhorn also recommended that the U.S. take a more reasonable position on Iran’s uranium enrichment program. Uranium enrichment is considered by the United States a step towards achieving nuclear weapons. “The Trump administration has taken the view that we should completely eliminate Iran’s uranium enrichment program,” Einhorn said. “That would be great if they would completely get rid of that. But we tried for years and years to do that and we didn’t have the leverage… We had the entire international community calling for that, now it’s virtually impossible. We have to be more realistic about that.”

The two of them took questions from the audience about Iran, and discussed the risk of Iran developing a covert nuclear weapons program. “I wouldn’t stake my life on it,” said Einhorn though he expressed his confidence in the U.S and Israeli intelligence community’s ability to discover any covert operations—especially given Iran’s track record of failing to hide its nuclear ambitions.

In addition to Einhorn’s earlier publications, he has two policy reports, one on constraining Iran’s nuclear program and the other on constraining Iran’s missile program, that will be released in the Brooking Institute Thursday the 28th. The reports will be available on the Crown Center for Middle East Studies website.