With two missed deadlines last year, and another one due at the end of March, negotiators are racing against time to reach a nuclear agreement with Iran.
Adding urgency to the talks is Israeli Prime Minister Benjamin Netanyahu's March 3 speech before the US Congress, which is viewed by political observers as a last-ditch effort to block a final deal.
But as the clock ticks, foreign policy observers said Netanyahu's plan could turn out to be a blessing in disguise for Washington and Tehran to achieve a historic breakthrough.
Suzanne DiMaggio, director of the Iran Initiative at the non-partisan think tank New America Foundation, said Netanyahu's "ill-advised" decision to bypass US President Barack Obama, in arranging a speech before the opposition-led US Congress, has only "weakened" his case against a possible deal with Iran.
"There's no doubt that Netanyahu's message will play well with those who oppose any deal," DiMaggio told Al Jazeera. "But there is very little chance that his appearance in Washington will derail the negotiations."
Netanyahu's not-so-secret feud with Obama, could also make it easier for Tehran to approve a deal, Iran expert Barbara Slavin wrote in a Voice of America online piece .
Even Netanyahu's former Mossad spy chief, Meir Dagan said that "the person who has caused the greatest strategic damage to Israel on the Iranian issue is the prime minister".
Netanyahu has been adamant in making the speech despite the White House's protest. He said the proposed nuclear deal is a "bad agreement that is dangerous for the state of Israel", and it is his duty to block it. The White House said Netanyahu, who is facing a re-election on March 17, is politicising US diplomacy.
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Tensions between the White House and Tel Aviv over Iran have further escalated in recent days, with the White House accusing Netanyahu's government of leaking details of the negotiations to derail a deal. "What is there to hide" if the US has a "good deal", Netanyahu asked recently. Obama's top national security aide, Susan Rice, replied that Netanyahu's action is "destructive" to US-Israeli relations.
At a US Congress hearing on Wednesday, US Secretary of State John Kerry, who is on top of the talks in Geneva, also questioned Netanyahu's judgement , recalling the prime minister's support of the invasion in Iraq.
As the US-Israel row drags on, the five permanent members of the UN Security Council, Britain, China, France, Russia, and the US plus Germany, known as P5 1, are continuing to work on a deal. But all eyes are now on Iran and the US negotiators as talks enter their final phase.
Those people who insist that Iran should absolutely have no nuclear programme, should also tell us how they seek to achieve this goal," Milani said. "What are the alternatives? Are they willing to go to war with Iran, if Iran does not agree to this demand?
The aim of the deal is to prevent Iran from building a nuclear weapon, while allowing it limited and verifiable number of centrifuges for energy and medical purposes. In exchange, Iran gets relief from international sanctions that have strangled its economy for years.
While no deal has been reached yet, Netanyahu said he has seen what's in the draft, and he found it objectionable. He insisted that a deal must prohibit all of Iran's uranium enrichment capacity.
But according to analysts, what Netanyahu, and his allies in the US Congress and American foreign policy circles are demanding, is unrealistic.
"It's more of a delusion than anything else," said Mohsen Milani, head of the Center for Strategic and Diplomatic Studies at the University of South Florida. "I'm afraid that the train has left the station, and is very unlikely to return," Milani told Al Jazeera, referring to the international understanding that Iran has the right to develop peaceful nuclear energy, and keep some of its nuclear centrifuges.
"It's very important to remember that the essence of any negotiations is give and take," Milani said. "Iran has already given major concessions to the P5 1."
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Instead of outrightly opposing a deal, Netanyahu and his allies should offer an alternative to the negotiations, foreign policy experts said.
"Those people who insist that Iran should absolutely have no nuclear programme, should also tell us how they seek to achieve this goal," Milani said. "What are the alternatives? Are they willing to go to war with Iran, if Iran does not agree to this demand?"
However, opponents of the deal continue to suspect that Iran is still intent on building a nuclear weapon.
DiMaggio pointed out: "All in all, I'd say the alternatives to a diplomatic agreement are very bleak." She added that a failed nuclear talks could trigger "escalation of hostilities" that could lead to calls for military action, "stoking the flames for a wider regional conflict".
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Returning from a recent trip to Tehran, Jim Slattery, a former US Congressman, said that Iran is ready to sign a deal, and that the US should "not miss an historic moment" in getting it through.
"The failure to complete an agreement right now, and the failure to improve this relationship with Iran, I think has very dangerous consequences for the US and for Iran," he told an Atlantic Council forum in Washington DC.
By insisting on delivering his speech before the US Congress, Netanyahu is "showing disrespect to the office of the president", Slattery said. "I am afraid that it's not going to be beneficial for Israel."
On the streets of Tehran, Iranians are still holding out hope for a deal, despite initial disappointments when talks failed to produce a deal last November, journalist Ruhollah Faghihi told Al Jazeera.
"Nobody likes to see this country sanctioned. The majority of people want to see this deal signed," Faghihi said, while acknowledging public anxiety about what "Israel and Arab countries" would do in preventing a deal.
"In my view, the people of Iran don't like to be pessimistic, that's why they try to be optimistic and hopeful about a nuclear deal, which leads to lifting all of the sanctions."
Source: Al Jazeera