What’s different in the latest round of talks between Iran and the West?

While they've gone quiet recently, the talks with Iran over its nuclear program are far from over.

The latest round wrapped up last week in Vienna. Iran and the six world powers at the table, including the US, have until the end of July to come up with a final agreement.

And if there is a deal, it would be one of the biggest diplomatic achievements in US-Iranian history. Barbara Slavin, senior fellow at the Atlantic Council and author of a book called "Bitter Friends, Bosom Enemies," says the Iranians came in with "tough demands."

"The Iranians are still talking about retaining and increasing the thousands of centrifuges that they have so that, at some point, they will be able to produce fuel for nuclear power plants," she says.

These demands, however, are not surprising Slavin says. She says this is the line the Iranians have been taking. What is different, she says, is the close relationship that has been forged between Iranian diplomats and their US counterparts — a historic feat in itself.

"This is a completely different process than what we saw under [previous] President [Mahmoud] Ahmadinejad," Slavin says. "Now you have daily contact between technical teams on both sides, sometimes between our secretary of state [John Kerry] and the Iranian foreign minister, between Wendy Sherman, our chief negotiator and the Iranians."

In other words, she says, meetings such as the recent one in Vienna are the "public moments" in the negotiation process.

"They are talking on the phone, sending emails on a daily basis, the negotiators refer to each other by their first names, they know something about each other's families. You never had this degree of intimacy between the United States and Iran in a negotiating form."

The way Slavin sees it, at this point, both sides have great interest in reaching a final deal.

"Iranians need sanctions relief, they need some positive momentum to get that society out of the funk that it's in, to convince the people that [President Hasan] Rouhani is the real deal and he can achieve something," she says.

The US also has an interest in seizing the opportunity to reach a deal with the Iranians.

"On Obama's side and on the West side, I think there is a desperate need for real diplomatic achievement in the Middle East with everything else going sour," she says, pointing to what's happened in Syria, the Israeli-Palestinian negotiations and Egypt.

For now though, Slavin remains cautiously optimistic about these talks.

"All of this does give me hope that they can finally reach an agreement. I am not saying this is guaranteed, I am not saying it's inevitable but there are profoundly good reasons why the two sides should reach an agreement," she says.

While they've gone quiet recently, the talks with Iran over its nuclear program are far from over.

The latest round wrapped up last week in Vienna. Iran and the six world powers at the table, including the US, have until the end of July to come up with a final agreement.

And if there is a deal, it would be one of the biggest diplomatic achievements in US-Iranian history. Barbara Slavin, senior fellow at the Atlantic Council and author of a book called "Bitter Friends, Bosom Enemies," says the Iranians came in with "tough demands."

"The Iranians are still talking about retaining and increasing the thousands of centrifuges that they have so that, at some point, they will be able to produce fuel for nuclear power plants," she says.

These demands, however, are not surprising Slavin says. She says this is the line the Iranians have been taking. What is different, she says, is the close relationship that has been forged between Iranian diplomats and their US counterparts — a historic feat in itself.

"This is a completely different process than what we saw under [previous] President [Mahmoud] Ahmadinejad," Slavin says. "Now you have daily contact between technical teams on both sides, sometimes between our secretary of state [John Kerry] and the Iranian foreign minister, between Wendy Sherman, our chief negotiator and the Iranians."

In other words, she says, meetings such as the recent one in Vienna are the "public moments" in the negotiation process.

"They are talking on the phone, sending emails on a daily basis, the negotiators refer to each other by their first names, they know something about each other's families. You never had this degree of intimacy between the United States and Iran in a negotiating form."

The way Slavin sees it, at this point, both sides have great interest in reaching a final deal.

"Iranians need sanctions relief, they need some positive momentum to get that society out of the funk that it's in, to convince the people that [President Hasan] Rouhani is the real deal and he can achieve something," she says.

The US also has an interest in seizing the opportunity to reach a deal with the Iranians.

"On Obama's side and on the West side, I think there is a desperate need for real diplomatic achievement in the Middle East with everything else going sour," she says, pointing to what's happened in Syria, the Israeli-Palestinian negotiations and Egypt.

For now though, Slavin remains cautiously optimistic about these talks.

"All of this does give me hope that they can finally reach an agreement. I am not saying this is guaranteed, I am not saying it's inevitable but there are profoundly good reasons why the two sides should reach an agreement," she says.