Having followed up a u-turn on cooperating with the UN's atomic energy watchdog with an all-out diplomatic offensive, Iran is confident it has averted a dressing down when its nuclear programme comes up for discussion at the IAEA.
Late in October, the Islamic republic went into reverse gear, agreeing to declare all to the International Atomic Energy Agency (IAEA), allow tougher inspections and suspend its controversial work on the nuclear fuel cycle.
Iran's pledge to comply came even after an IAEA deadline for answers was denounced on state television as a Zionist-US plot, and a succession of powerful hardliners lined up to urge Iran follow the path of its "axis of evil" stablemate North Korea and quit the Non-Proliferation Treaty (NPT).
Had Iran ignored the IAEA, the chances were it would have been referred to the UN Security Council. The result could have been sanctions, and even an open invitation for arch enemy Israel to confirm indications it is considering military strikes against Iranian nuclear facilities.
And if the option of condemning Iran - still demanded by the United States - is chosen despite the very public gesture of goodwill that Iran made when the foreign ministers of Britain, France and Germany visited last month, Iran has made it clear that another u-turn could be in the offing.
In recent weeks, Iran has sent out its emissaries to Moscow, Brussels, Tokyo and Beijing - all carrying the message that the country has complied and a slap on the wrist for its admitting to past violations of the NPT would be in bad faith on the part of the IAEA's board of governors.
"We have made this decision to comply under fierce opposition domestically," Foreign Minister Kamal Kharazi was quoted as telling Japanese Prime Minister Junichiro Koizumi in a meeting last week - part of a tour also aimed at winning the support of China.
"It was a problem that we did not report some nuclear activities, but they were not for military purposes," Kharazi said, appealing for Japanese support at the November 20 IAEA board meeting in Vienna.
A similar diplomatic offensive has been made by the secretary of Iran's Supreme National Security Council, Hassan Rowhani, when he made a rare outing to meet with Russian President Vladimir Putin in Moscow and top EU officials in Brussels.
"We hope the Tehran declaration" - the pledge of compliance from Iran made when the EU's big three foreign ministers visited - "will be a starting point for the development of our relations," Rowhani was quoted as saying on state television after visiting Brussels.
But while Iran is still threatening another u-turn if things do not go its way at the IAEA, the pledges of support won on these visits has led to increasing confidence in Iran that it can avoid sanction in Vienna.
And with sound reason, diplomats say.
"Of course, logic would dictate that Iran should be criticised in some way for past violations, just for the record," a European ambassador in Tehran said. "After all, Iran has owned up to some two decades of violating the NPT."
"But a condemnation would be a major loss of face for Iran, and that could empower the hardliners. That in turn would detract from the overall objective of the IAEA - which is making sure we can keep a close eye on Iran in the long-term."
If Iran makes it through the Vienna meeting unscathed, it will be something of a diplomatic victory for an Islamic republic determined to foil a concerted pressure campaign from Washington.
But, diplomats say, it will not be end of the story.
"There may be a lot of face saving involved when the IAEA resolution is passed," a Western diplomat explained. "But we must not forget that by agreeing to sign the additional protocol, Iran will now be subject to the kind of unprecedented scrutiny it wanted to avoid. And that makes me think this is only the opening of a new, more sensitive chapter."