A rather chilly reception greeted the IAEA delegation when it arrived in Tehran on Wednesday night for nuclear talks. But it was not an issue of the Iranians giving them the cold shoulder, as it turns out; it really was just the weather.
In fact, things began to warm up, or so it seems from comments from both the IAEA (the UN's International Atomic Energy Agency) and the Iranians.
The talks finished on December 13, with the promise of more talks in the Iranian capital on January 16. Meetings so close to one another are a good sign. If they don't signify a breakthrough, they signify progress regarding the biggest sticking point between the two sides access to Iran's most sensitive and important military facilities.
The IAEA's chief inspector, Herman Nackaerts, told reporters they had "good meetings". Iran's ambassador to the IAEA, Ali Asghar Soltanieh, also said the talks were constructive, "Intensive negotiations were held ... There was good progress made," Iranian media quoted him as saying.
While good progress is a big step away from an agreement, and possibly averting war, it's something considerable. Until the meeting, both sides had refused to come down off the devil's donkey, to quote the Persian proverb, meaning they had been acting stubborn. But comments after the meeting suggest at least a willingness to consider their positions.
The IAEA talks are crucial in the two-track approach to solving the nuclear issue. The first is the political one - the United Nations Security Council (the P5+1, permanent members of the UNSC) which is trying to avoid a military showdown with the US and Israel. But these talks are stalled.
The second are the technical talks, regarding inspections and the nitty gritty conducted by IAEA.
Between the IAEA and Iran is a military problem though, not a nuclear one Parchin.
The IAEA created its own obstacle by insisting on access to the military base, south of Tehran, even though the Iranians have been clear they'll never agree to it unless it's on their terms. Iran wants a framework agreement first, which spells out exactly what inspections will entail. If you read between the lines, the two sides are getting closer to this very agreement. It also wants the IAEA to guarantee security and secrecy, given the important nature of the site in Iran's defence development.
Why Parchin is so important to the IAEA dates back a decade that's when the IAEA claims Iran had conducted high explosive tests there, using the type of explosives that can be used as a trigger for a nuclear warhead. Satellite imagery made available this year by the Institute for Science and Security, a US think-tank (ISIS), shows before and after pictures of Parchin.
The images show Iran has landscaped the military base, using heavy machinery to remove top soil, demolish buildings and according to the newest images, released just days ago, install a new security perimeter to bolster defences there. The IAEA suggests all this is proof that Iran is trying to cover up evidence of these explosive tests. Iran denies this outright.
For the record, Iran has actually allowed the IAEA access to the site - but access was limited.
Until the talks, it wasn't just the Iranians who wanted the IAEA to leave this issue alone even some Western diplomats said the same thing if it's the past, its the past there are enough issues that are in the way, not just with the IAEA but with the P5+1, neither side needs another one.
But what happens if both sides get down from the devil's donkey is unclear. And at the moment, so too is how they're going to do it.