The US and Iran have attacked each other in public to sell nuclear talks to skeptical audiences at home. But harsh words have eroded trust.
The Obama administration had previously used 'dismantle' to describe a final deal on Iran's nuclear program, but this went down badly with Iran. Obama said he would veto any new sanctions.
The UN announced Sunday that it had invited Iran to attend Syria peace talks in Geneva. The unexpected decision could scuttle the long-awaited meeting.
Iran turned down a limited US invitation to the Syria peace conference, but the two have an increasingly common interest in stemming the rise of Sunni militancy in places like Iraq.
How a possible thaw with the West is viewed in Iran – on the factory floor, at Friday prayers, and in government suites.
The US government has been lying for years about Robert Levinson, a man kidnapped in Iran after being sent there as part of a rogue CIA operation. Some media have been playing along.