Hassan Rouhani's victory in Iran's presidential election has boosted cautious hopes for a change in the country's troubled relations with the west – amid warnings that any new policies would have to be authorised by the hardline supreme leader, Ayatollah Ali Khamenei.
The US congratulated Rouhani – using his clerical title, "Sayyid" – and pledged to "engage Iran directly" to find a "diplomatic solution that will fully address the international community's concerns about Iran's nuclear programme". Britain called on him to "set Iran on a different course for the future".
Arab states sent formal greetings but commentators emphasised the sharp divisions over Tehran's support for Bashar al-Assad in Syria – which mirrors Saudi Arabia's backing for the rebels seeking to overthrow him. Syria's opposition coalition called on Rouhani "to recognise the will of the Syrian people as they persevere in the face of foreign aggression and tyrannical rule".
Iran is also the patron of Hezbollah, the Lebanese Shia movement that in recent weeks has been fighting openly alongside the Syrian army. The involvement of Iranian security personnel in Syria has been far more discreet.
Israel, whose nuclear monopoly in the Middle East is threatened by what Tehran insists is a peaceful nuclear programme, was dismissive. "The international community must not give in to wishful thinking or temptation and loosen the pressure on Iran for it to stop its nuclear programme," warned Prime Minister Binyamin Netanyahu.
Rouhani gave little away in his first public comments, saying: "The nations who tout democracy and open dialogue should speak to the Iranian people with respect and recognise the rights of the Islamic republic."
Expectations for significant international repercussions from Iran's election result are generally modest. Under Iran's hybrid system ultimate power still rests with Khamenei. Elected presidents do not have the freedom of action to change course on major security, defence and other foreign policy issues.
Still, Rouhani has views of his own and seems likely respond to positive signals – from the US in particular. It was during his talks with EU governments from 2003 to 2005 that Iran suspended elements of its nuclear programme. It was only when Mahmoud Ahmadinejad became president that Iran aggressively accelerated uranium enrichment.
During the election campaign he linked the state of the economy to the nuclear standoff and attacked Khamenei's candidate (and Iran's current nuclear negotiator) Saeed Jalili, for incompetence on the issue, saying that his dogmatic approach and "slogan of resistance" had not achieved much. Rouhani also suggested in an interview that the Americans had first broached talks and Khamenei vetoed them – contrary to the standard narrative in Tehran which portrays Iran as always reasonable.
"We could be in for a rethink period on foreign policy," suggested one veteran Iranian analyst. "But it could be a long process of gradual change rather than a overhaul. Rouhani's 16 years in the national security council puts him in a very strong position in understanding and handling the policy-formation process and the people and the agencies involved."
For some observers, Rouhani's candidacy suggested a parallel with the decision in 1988 to appoint Akbar Hashemi Rafsanjani as commander of the army with a view to extricating the country quickly from its bloody eight-year war with Iraq. Rafsanjani was elected president the following year.
In this optimistic view, Rouhani is the right man to lead a new initiative to allow Iran to disengage from its lonely and economically debilitating battle over the nuclear issue. "As the author of Iran's previous dabbling in nuclear concessions, he can be the fall guy, yet again, for a deal that the [supreme] leader wishes to disavow," said Suzanne Maloney of the Saban Centre for Middle East Policy.
The key question is how much room for manoeuvre he will be permitted to have by Khamenei, the powerful Revolutionary Guards and intelligence establishment. His cabinet, observers say, will be important to calm fears in the conservative camp that he is not planning a coup against them.
"The [supreme] leader, it would appear, has accepted that things are not right and that a change was needed," argued Ali Ansari of St Andrews University. "What we do not know is how far he has accepted that the crisis in the country is real. I remain anxious that all these raised expectations will founder on the obstruction of a leader who has not fully heard the message or understood what people want."If Khamenei thinks that Rouhani can just introduce cosmetic changes to sweeten the west and get sanctions lifted, then I fear that he [Khamenei] will be sadly disappointed. But so will all those Iranians who want to see real change. Rouhani has to deliver substantive changes otherwise it's not going to work."