Iran's chief negotiator, Saeed Jalili, said before leaving Tehran that the talks were an "opportunity and a test." Chosen by Mr. Ahmadinejad, Mr. Jalili is a known hard-liner, a veteran of the Iran-Iraq War who Western diplomats have said specializes in "monologue."
A host of issues – chief among them continued confrontation over Iran's nuclear program, and the possibility of "crippling sanctions" – have raised the stakes for diplomats on both sides.
The UN International Atomic Energy Agency (IAEA) reported in August that Iran now has 8,000 centrifuges spinning to enrich uranium, to create nuclear material that can be used to fuel power plants – as Iran says is all it wants to do – or, if enriched to a far higher degree, for use in weapons, which some Western governments suspect is Iran's hidden purpose.
Those suspicions were heightened last week by Iran's acknowledgement that it had been working secretly for years on a smaller uranium enrichment facility, a belated admission that was "on the wrong side of the law" and a "setback to the principle of transparency," according to Mohamed ElBaradei, the chief of the United Nations nuclear watchdog agency. The facility is adjacent to a base of the Revolutionary Guard, the same elite force that oversaw testing this week of Iran's most advanced medium-range missiles, which – like previous missiles – are capable of reaching Israel as well as US military bases in the Middle East.