President Donald Trump, in between blockading the Strait of Hormuz and posting blasphemous AI images of himself as Jesus, claims he still wants to strike a deal with Iran’s government to end the current conflict, reopen the Strait, and curtail the country’s nuclear program.

So far, he’s been unsuccessful — and during his first term in office, he tore up the US’s previous nuclear agreement with Iran, negotiated under Barack Obama in 2015.

To find out how the US and Iran got to yes last time — and why they haven’t under Trump — Today, Explained co-host Noel King spoke with former Deputy Secretary of State Wendy Sherman, who led the Obama administration team that got a nuclear deal with Iran.

Below is an excerpt of their conversation, edited for length and clarity. There’s much more in the full episode, so listen to Today, Explained wherever you get podcasts, including Apple Podcasts, Pandora, and Spotify.

What do you think it would take for the US to get a new deal with Iran right now?

It depends on what the objectives are for the president and for Iran. Right now, President Trump wants to make sure Iran doesn’t have a nuclear weapon. He wants to open the Strait of Hormuz, he wants to stop Iran from funding proxies like Hezbollah, Hamas, and the Houthis in Yemen, because he thinks they create a risk for Israel, who is our ally and all of the countries in the Gulf region.

Iran, on the other hand, has control of the Strait of Hormuz, so they’re looking to maintain that leverage because it allows them to project power in the region. They want to ensure that they maintain a right to enrichment and they want to be able to continue to have relationships with Hezbollah and Hamas and the Houthis.

There’s a big gap and it’s curious, because the negotiation team on our side is quite small. The negotiation team on their side includes people like Abbas Araghchi, who was my counterpart during the 2015 negotiations. He’s now the foreign minister and he knows every single detail of that deal.

Back when you were negotiating with Iran, were there moments looking back when you thought, This is just not going to happen?

Absolutely. There were many points along the way where I said to my counterparts, “If you can’t do it, you can’t do it.”

We thought we were very close to a set of parameters and the supreme leader at the time gave a speech and set out a whole new set of parameters that I think surprised even his foreign minister.

We had to figure out how we could get from where we were, which we thought was on our way to a deal, to now consider what the supreme leader had publicly said.

We know, in part because President Trump articulated this early and often, that there were some Americans who thought we could have gotten a better deal with Iran. What do you hear as the main complaint and what do you say to those critics?

The critics say that the strongest part of the deal only lasted for 15 years. They wanted it to last forever. We argued that it gave us what is called a one-year breakout timeline so that we would have a year — if somehow we discovered Iran was cheating, which we thought was highly unlikely — to do something about it.

I think some critics wanted to go to war. They thought they could create a regime change. We constantly said to the United States Congress, if we risk war, it could close the Strait of Hormuz, it could increase the gas prices, it could take down the international economy, it could mean the lives of our military and an enormous cost to our economy and to American citizens.

Are the right people at the negotiation table?

I find it difficult to believe that Vice President Vance, Steve Witkoff, and Jared Kushner can be successful in two weeks. I fully suspect that the negotiations will continue beyond two weeks if they get any traction at all.

I think part of the reason the vice president is there is because Steve Witkoff and Jared Kushner, who has no formal role in the government, don’t have credibility with Iran because twice before when they were negotiating with Iran, we attacked.

It’s hard to believe that someone’s going to keep negotiating with you if the two other times, they’ve attacked in the midst of negotiations.

Is there a risk this time around that the US comes out weaker and Iran comes out stronger?

I think it’s very hard to be that reductive. There are parts of Iran that are weaker. They don’t have the navy they once had. They don’t have the missile programs they once had. They don’t have the nuclear programs they once had.

They can rebuild all of that and if they get millions of dollars in tolls and sanctions relief from the United States, they will be able to rebuild all that capacity faster. But at the moment they have been set back.

The United States, in my view, has been set back. We have just spent billions of dollars. We have reduced our inventory of weapons that we may need for other theaters. We have undermined our alliances. We have put Russia and China in stronger positions. We have removed oil sanctions from Russia and oil sanctions from Iran, already putting money in their coffers, giving Russia more money so they can prosecute their horrible and illegal war against Ukraine.

All of this has cost everyday average Americans much more out of their pocketbooks. The regime in place in Iran now is more hard line than the one before, if you can believe it, and may decide it must have a nuclear weapon in order to deter future attacks.

If Iran decides it wants a nuclear weapon, I can assure you many other countries, even some of our closest friends around the world, will think they need a nuclear weapon as well.