There's been no official word that if progress isn't made in Moscow this week in dismantling Iran's nuclear program, both sides will probably end the charade and give up the effort. But that is the consensus opinion from Europe and the US.
In Iran, President Mahmoud Ahmadinejad said Tehran would be prepared to stop enriching uranium to a higher level - a process that could be used to make nuclear arms - if the six powers agreed to meet its needs for the fuel. But it is not clear how much influence Ahmadinejad has over the negotiations and whether his remarks reflect Tehran's position in the talks.
Experts and diplomats said a breakthrough was unlikely at the meeting in Moscow, where the world powers are wary of making concessions that would enable Tehran draw out the talks and give it more time to develop a nuclear weapons capability.
Iran strenuously denies it has any wish to obtain such weaponry and says it only wants nuclear technology to generate electricity.
Israel has threatened to bomb Iran if no solution to the dispute is found, oil markets are nervous over the prospect of intensifying regional tensions and the frail world economy can ill afford a further increase in crude prices.
"The atmosphere was fine, business-like and good. We hope this translates into a serious political commitment by the Iranians to address our proposals," a European Union spokesman said after the talks started in the Russian capital.
Iran may very well take a deal where they give up the further enrichment of uranium from 5% to 20% -- just as long as they get to keep the stockpile they have. Their current supply could give them 5 or 6 bombs by most estimates. How long it would take to turn that uranium into bomb grade material is unknown, but most estimates range from 6 months to a year.
Israel can't afford to wait that long, so without signs that the Iranians are giving up their effort to make a bomb, an attack this year - probably before the American election - is a real possibility.