Washington---US President Barack Obama, eager to resolve at least one intractable conflict in his final two years in office, has his eye on a major prize: reconciliation with Iran.
Thursday's agreement on a road map for the final phase of negotiations on a nuclear accord could open a way to a broader realignment that would redraw the map of the Middle East.
But analysts warn that the long-time foes remain far from a rapprochement and any future cooperation would be limited.
"In Barack Obama's head, there's this fantasy of a grand bargain, an alliance with Iran, and of reconstructing the architecture of the region for a paradigm shift," said Joseph Bahout, a visiting scholar at the Carnegie Center.
"This is the fantasy of the Obama administration, but he knows it will never happen because Iran is a lot colder.
"They'll take the nuclear deal, but everything will remain business as usual," he added.
Relations between Tehran and Washington are haunted by the 1953 coup, orchestrated by the CIA, which overthrew Iranian prime minister Mohamed Mosssadegh and restored royal rule.
Shah Mohammad Reza Pahlavi was overthrown in turn in the 1979 revolution that brought Ayatollah Khomenei's Islamist and explicitly anti-American government to power.
The divide between the powers has been deepened by decades of hostile rhetoric.
The United States is regularly denounced as the "Great Satan" by Iranian leaders, and Washington has slammed Tehran as a "rogue state," part of an "axis of evil."
Obama hailed the "historic understanding" with Iran Thursday, and said he is willing to engage with Iran "on the basis of mutual interests and mutual respect."
But he sent Tehran a strong warning.
"This deal alone -- even if fully implemented -- will not end the deep divisions and mistrust between our two countries," he said.
"So make no mistake: We will remain vigilant in countering those actions and standing with our allies," Obama added, referring to what he called Iran's "sponsorship of terrorism."
- Major stakes -
The first signs of a potential thaw came in 2013, when US Secretary of State John Kerry and his Iranian counterpart Mohammad Javad Zarif met.
The closed-door encounter led to talks that have taken place over the past 18 months with Britain, China, France, Russia, the United States and Germany, known as the P5+1, to hammer out a complex comprehensive nuclear agreement.
Both sides have major stakes in seeing the deal succeed.
Removing or delaying the threat of a nuclear-armed Iran would be a stunning victory for Obama.
AFP
