But here are five reasons why these negotiations might stand a chance.
One: Tough sanctions as imposed by the Europeans and the Obama administration have had the desired impact. The rising costs of sanctions and Iran's increasing international isolation are key factors in Tehran's decision to look favorably on talks.
Two: The good cop/bad cop routine by the United States and Israel has worked - whether or not the strategy was intentional. Israel's efforts to persuade President Obama to attack Iran and Obama's efforts to delay any Israeli attack, galvanized Tehran's attention. Even if Iran's leaders doubted the threat was real, they weren't certain - which focused their mind on diplomacy.
Three: A history of failed talks on the nuclear issue has given Western diplomats experience in dealing with Iran's delaying tactics. This time the so-called P5 + 1 - the United States, Britain, France, Russia, China, and Germany - will insist on concrete results from the next round, along with a specific time frame.
Four: The leadership situation has changed in Tehran. Supreme Leader Ayatollah Ali Khamenei nixed past efforts by moderate President Mohammad Khatami and the mercurial President Mahmoud Ahmedinejad to work out a deal. Apparently, he was unwilling to see them get the credit, and suspicious of what they might accept.
But now that Ahmedinejad's power has dimmed, and Khamenei has consolidated his own, he may finally feel ready to reach an accord with the West. Especially as President Obama has made clear that his goal is a change of Iranian behavior, not a change of regime.
"I firmly believe the chance exists for a deal," says Hossein Mousavian, a former Iranian nuclear negotiator and a visiting scholar at Princeton University. "On critical issues relating to national security, the supreme leader is the ultimate decision-maker. Therefore, there would be no major internal objection."
Five: Both sides seem to have clarified their red lines on what is and is not acceptable regarding the Iranian nuclear program. "Nine years of negotiations have failed," says Mousavian, "because the red lines were not clear."
For Iran, the red line is the right to enrich uranium. This is permitted to signatories of the Non-Proliferation Treaty - for the peaceful use of nuclear energy. For the P5 + 1, the red line is guaranteed assurance that Iran will not divert enrichment toward the making of a nuclear weapon.
Over the last decade, the P5 + 1 demanded a suspension of all Iranian enrichment, until Iran stopped stonewalling inquiries by U.N. nuclear inspectors about a possible weapons program. Meantime, the Iranians started to enrich some uranium to 20 percent, which is much closer to weapons grade than the 3.5 percent level needed for an energy reactor. And they began using a bomb-proof facility known as Fardow buried deep under a mountain.
At Istanbul, there were signs - only signs - of a formula that would preserve both sides' red lines: Iran would stop enriching to 20 percent and transfer most or all of this uranium out of the country, to be returned as fuel rods for its research reactor. This would diminish some of Israel's immediate fears.
Iran would also agree to intensified inspections and answer U.N. queries on weapons issues. If Iran delivered on its promises, new economic sanctions - set to kick in in July - could be postponed. And Iran's right to peaceful enrichment could be confirmed.
Of course the question marks are endless. Iranian officials want economic sanctions lifted immediately, while P5 + 1 officials say they will only be lifted in stages, after progress. The West wants to see Fardow closed.
Israel remains skeptical and wants to see Iran's enrichment process wholly ended. Khamenei's fatwa against nuclear weapons hasn't convinced most Israelis that Iran isn't a threat. The possibility that the supreme leader believes Iran has gone as far as is possible - for now - with acquiring nuclear knowhow leaves Israelis cold.
Yet, given the risks of another Mideast war, it just may be possible to find a formula that all sides can live with. Whether it's probable will become clearer as the next round of talks nears.
"Istanbul was the entry ticket," says Michael Adler, a top expert on the nuclear talks and at Washington's Woodrow Wilson Center. "The real game begins in Baghdad. And the P5 + 1 will have to see something practical on the ground."
E-mail Trudy Rubin at email@example.com.