Guardian's author bio line:

Hossein Mousavian is the former spokesperson of Iran's nuclear negotiating team and author of the book Iranian Nuclear Crisis: A Memoir, published by Carnegie Endowment for International Peace

To find out more, I started with the Wikipedia entry on Hossein Mousavian.  Then  I followed the footnote link to this sentence there:

Since his arrival in the US, he has made many media appearances, acting as an unofficial spokesperson for the Iranian regime [1].

To this blog entry at "Iran Media Focus":

Slippery Seyed
Sept 20, 2012

Seyed Hossein Mousavian is a complex character.  He is pro-regime, but currently out of favor for his apparent lack of loyalty to ‘Supreme Leader’ Ali Khamenei.  Mousavian has held a plethora of official positions: [....]

Then went to a later entry on the same blog on Mousavian:

In an Iranian game of chess, Mousavian is the ultimate pawn
Dec 10, 2012

People are still falling for it.  Slippery Seyed is back to his old tricks and apparently has some new fans.  Seyed Mousavian, for those who do not remember, is a former Iranian nuclear negotiator and spokesman for Khatami’s nuclear team.  I have discussed his sophisticated tactics on behalf of the Iranian regime in previous posts, to be found here and here).

In the National Interest, Mousavian recently penned a 10 point elucidation of why “Iran doesn’t want the bomb”.  If it was written by someone else and entitled ‘Why Iran shouldn’t get the bomb’, it may have some practical use.

Unfortunately, slippery Seyed is playing games.  How do we know?  Well, because the action of the country he claims does not want the bomb… does not match his own misleading and tendentious analysis. [....]

So as has been the case for like a decade in this grand cat-and-mouse diplomatic game, (when BTW I constantly was told "we are going to war next month" and never believed it,) I don't know which argument to believe about what is really going on here with negotiations.

So I go look what else is on the The Guardian site on Iran right now, because I know they only recently asked the highly respected Tehran Bureau News Blog to become a part of their site, but I didn't find anything on topic at Tehran Bureau.

I did however find this interesting article elsewhere at The Guardian, my bold:

Iran's Obama billboard: what it really means
Tehran's latest propaganda offensive shows Barack Obama on a huge mural side by side with a seventh-century Shia villain
By Roland Elliott Brown, Shortcuts Blog @ The Guardian, 20 Jan 2013

For connoisseurs of political symbolism, Tehran – a city whose best billboard real estate is devoted to Islamist ideology – is a feast. Government-sanctioned murals [....]

The Tehran mural aims to invert this occult symbolism by recourse to Shia tradition. The villain Shemr belongs to the narrative of Hussein's martyrdom at the Battle of Karbala in 680, the trauma that split Muslims into Sunni and Shia denominations. The Shia, or "Party of Ali" (Muhammad's cousin and son-in-law) sought hereditary leadership of Islam. After the murder of the Caliph Ali, and the death of Ali's son and successor Hassan, Ali's younger son Hussein clashed for succession with the Umayyad Caliph Yazid, who sent Shemr's army to destroy Hussein and his followers. Shemr offered some of Hussein's supporters a "letter of protection" in exchange for betraying him, but they refused.

In the mural, Shemr extends a similar letter to the viewer, as he and Obama utter the words Ba ma bash – "be with us" – playing on the president's name, and insinuating that anyone who still likes Obama in the wake of tightening sanctions – or who advocates meeting American, EU, or International Atomic Energy Agency demands over Iran's nuclear programme to avoid conflict – is a traitor to the faith. Obama, the state insists, is a "Hussein" unworthy of loyalty.

And then I thought, what are the clues in all of this about which side is being more warlike and which side is being more reasonable and trying to negotiate in good faith to avoid war? And which side is more likely to be attempting to get to the truth and which side is likely to be pushing more incendiary propaganda to cover up the truth? The West, who invites a Mousavian to be a visiting scholar and offers venues like The Guardian's Comment is Free in which he can publish his opinion, is the one causing all the trouble? The West is the one that is unreasonable and intransigent and trying to go to war? Once again, I doubt that for the umpteenth time over a decade.

My bold:

IAEA Mission to Iran Returns
IAEA website, Top Stories and Features, Jan 22, 2013 (UPDATE of 18 January 2013)

UPDATE: The date of the next meeting has been changed to 13 February 2013.

Returning from a two-day bilateral meeting with Iranian officials held in Tehran, Iran, IAEA Deputy Director General for the Department of Safeguards, Herman Nackaerts, delivered the following remarks to the press that gathered at Vienna International Airport on Friday morning, 18 January 2013:

"We had two days of intensive discussions.

" Differences remain, so we could not finalize the structured approach to resolve the outstanding issues regarding possible military dimensions of Iran's nuclear program.

" We have agreed with Iran that we will meet again on the 12th of February.

" What I can also say is that on this occasion no access was granted to Parchin."

(Note to Media: We encourage you to republish these stories and kindly request attribution to the IAEA)

No deal in Iran-IAEA talks
New meeting scheduled for February 12 after talks between Tehran and UN atomic agency falter.
Associated Press via Al Jazeera,  Jan 17, 2012

Senior officials at the International Atomic Energy Agency, IAEA, have ended two days of talks with Iranian officials over allegations that Tehran may have carried out tests on triggers for atomic weapons, the Fars news agency reports.

Thursday's report went on to say that the two sides agreed to another round of negotiations scheduled for February 12.

A senior IAEA diplomat, demanding anonymity because he is not authorised to speak on the matter, said that the two-day talks were "not going very well", shortly before they came to an end.

Herman Nackaerts, head of the UN team, had hoped the IAEA would be able to "finalise the structured approach'' that would outline what the agency can and cannot do in its investigation.

The IAEA, whose mission is to prevent the spread of nuclear weapons, has been trying for a year to negotiate a so-called structured approach with Iran giving the inspectors access to sites, officials and documents for their long-stalled inquiry [....]