NEW YORK // It was a frustrated spokeswoman who stood at a podium at the US State Department last week and tried to explain why, yet again, six-party talks with Iran over its nuclear programme were being postponed.
"They've been coming back with preconditions on the modalities for the talks," Victoria Nuland told reporters on Friday. "We're not to the point of substance yet."
But even if Iran and the world powers led by the United States can manage to restart talks, it is likely that the impasse will remain as neither side has shown the willingness to meet the other's minimum requirements, let alone set the stage for a comprehensive deal, analysts said.
"Theoretically there is greater manoeuverability in Washington right now, but whether that will be utilised remains to be seen," said Trita Parsi, an expert on Iran-US relations and president of the National Iranian American Council, a Washington-based non-profit organisation "dedicated to advancing the interests of the Iranian American community".
"If both sides come to the table for the fourth time now and essentially insist on the same things they insisted on in the first meeting, I don't think we should be surprised if there's no breakthrough."
The US and the other members of the P5 + 1 - Britain, Germany, China, Russia and France - have shown no sign that they will soften or lift economic sanctions, Iran's chief demand.
For its part, Iran has offered no willingness to acquiesce to dismantling major aspects of its nuclear program, given that they are its main points of leverage in future negotiations.
While a comprehensive deal is unlikely in the short term, an important intermediate deal that would break the gridlock and begin the process of building trust is potentially within reach because Iran has previously appeared willing to end high-grade enrichment.
"This is not an issue that is impossible to resolve," Mr Parsi said.
2013 was thought to be the year that such a breakthrough would finally occur, both because the stakes are higher - many experts predict Iran could finally achieve its nuclear capability this year - and the urgency greater for Mr Obama, whose stated commitment to use force as a last resort could be put to the test if diplomacy fails.
So far this year, while the P5 + 1 have been willing to meet, it appears that the Iranians are the main cause of the delays.
European Union officials said Friday they hoped a new date in February could be agreed upon soon.
Some observers believe the delaying tactics are an attempt by Tehran to string along the world powers while its grows ever closer to having the capability to make a nuclear bomb.
But others see the foot-dragging as possibly either a tactical calculation, or a sign of internal divisions.
Perhaps Iran is hoping the move will force a more substantive offer, as it doubts that the P5 + 1 package will be significantly different from the one put forward in the last round of talks, and is seeking to avoid being blamed for their failure, Mr Parsi said.
The delay "could also be an attempt to dismantle the narrative that sanctions are bringing Iran to its knees," and the sanctions give the west enormous leverage, he added.
The delay could also be the result about disagreements among Iranian leaders about strategy.
"The Iranians can't reach internal consensus about what they want to do, what their red lines are and what they want to get out of negotiations," said James M Acton, an expert on Iran's nuclear programme and a senior associate at the Carnegie Endowment for International Peace.
Iran's presidential campaign season, which begins in late spring, could also be a factor, with some leaders wishing to avoid any domestic instability - and political constraints - before the June 14 polls.
Whatever the motivations, the analysts agreed that Iran's calculus will likely fail to pressure Washington.
"The US has to be prepared to put a generous offer on the table when the time comes, but there's no point in doing that until you are seriously in a negotiation," said Mr Acton. "If you make that at the beginning the Iranians will just pocket it and say 'What more will you give us?'"
But the Obama administration may also be overplaying its hand, particularly in regard to the ability of sanctions to force the Iranian regime to give up its nuclear programme, which it claims is for domestic use but which the West says is for building a weapon.
The sanctions have been successful in crippling the Iranian economy, and Tehran undoubtedly wants negotiations to result in relief from them. "But there has been an expectation that the Iranians would really soften their position and clearly we are not seeing any signs of that," said Mr Parsi.
Many analysts and former US officials in Washington have argued publicly since Mr Obama's re-election that instead of waiting for the Iranian regime to break the cycle, he must now offer sanctions relief in return for initial concessions that seem immediately possible, like the halting of 20 per cent enrichment rather than all enrichment.
"The deal that I hope the US is willing to offer Iran is that it will be allowed to enrich to five per cent, which is enough for civilian nuclear reactors, but subject to enhanced safeguards and verification by the IAEA [International Atomic Energy Agency]," said Mr Acton.
The risk for the Obama administration would be that if this deal failed to entice the Iranians, the course of action would again be set for a military solution.
But with little stomach in Washington for another war in the Middle East, and statements last week by the Israeli minister of defence, Ehud Barak, that Israel would not take unilateral action, Mr Obama may be content for now to wait until the Iranians are ready to talk.
"Dragging on [agreeing to talks] doesn't reduce Obama's options," Mr Acton said.
What his advisors should be preparing for is how to handle the inevitable political fallout in Congress from making concessions to an unpopular Iran.
"There's a political price to be paid [for compromise] in Washington and in Tehran, and it requires courage, persistence and dedication to reach that solution," said Mr Parsi. "That is what we have failed to see so far."