Secretary Clinton's overtures to Russia – including last week's meeting with Russian Foreign Minister Sergei Lavrov – are also partly seen as an effort to enlist Russia's support for a new American approach to Iran.
Yet such steps are widely seen as maneuvering around the edges, and they would have to be followed by some larger action – for example, a letter from Mr. Obama to Iran's supreme leader, Ayatollah Sayed Ali Khamenei – for US engagement with Iran to really get off the ground, Iran analysts say.
"Inviting Iran to a conference on Afghanistan or having ambassadors meet in Baghdad, those are tactical moves, and Tehran is saying it's not interested in tactical overtures anymore," says Alex Vatanka, Islamic affairs analyst at Jane's Information Group in Alexandria, Va. "The Iranians, including the supreme leader, are interested in relations with the US, but what they are interested in is a strategic shift in America's perceptions of the Iranian regime."
The senior European official says he made the same point to his US counterparts, including Dennis Ross, who was recently named a special adviser to Clinton who will focus on Iran. The Iranians see the prospect of relations with the US in broader terms than their nuclear program, the official says.
"In a sense, the future of the regime is at stake," he says. "Their first and only [concern] is the survival of the regime."
That means the Iranians are likely to move slowly on any diplomatic feelers the US may send out. Already, the Iranians are sending signals that they have no intentions of responding quickly.