Denying Iran's opening carries its own risks: Our view

• Iran%27s oil revenue is down 58%25 by U.S. estimates.
• Half of Iranians struggle to pay for food and shelter.
• Rouhani promised improvement%2C which can come only in exchange for nuclear concessions.

From the moment Hasan Rouhani, a relative moderate, was elected president of Iran in June, critics have worried that he'd put a friendlier face on Iran's nuclear program without actually changing it. Sure enough, Rouhani has marched steadily away from the confrontational approach of his bombastic predecessor, Mahmoud Ahmadinejad.

If Rouhani's smile is just a mask, though, it's a very good one. So good in fact that only the hardest of hard-liners — most notably Israeli Prime Minister Benjamin Netanhayu — are dismissing the gestures he has been making. In a remarkable shift from a year ago, Rouhani and President Obama exchanged conciliatory words in separate speeches at the United Nations on Tuesday.

Perhaps this will lead where the skeptics fear: to a stall that allows Iran to build nuclear weapons before a U.S. attack to destroy its nuclear facilities. Nevertheless, the Rouhani initiative is a last, best chance to end Iran's nuclear program without military conflict, and there are reasons to view this new opening as credible:

• Rouhani won election in an upset because sanctions aimed at the nuclear program are biting. Iran's oil revenue is down 58% by U.S. estimates, and a Gallup poll found 50% of Iranians struggling to pay for food and shelter . Rouhani promised improvement, which can come only in exchange for nuclear concessions. His initiative is precisely the result the U.S. and its allies have sought.
• Rouhani has credibility on the nuclear issue. In 2004, as Iran's nuclear negotiator, he persuaded Iran's leadership to suspend uranium enrichment in hopes of getting a breakthrough in negotiations — only to be sent into political exile when diplomacy failed. A similar concession now would add substance to Rouhani's words.
• To nearly universal surprise, Iran's supreme leader, Ayatollah Ali Khamenei, has publicly backed Rouhani's initiative, ordering Iran's Revolutionary Guards to stay out of his way and, as Obama noted, issuing a fatwa against nuclear weapons .
• The nuclear maneuvering has come with other confidence-building signals. In stark contrast to the Holocaust-denying Amadinejad, Rouhani offered a greeting to Jews on Rosh Hashanah , and the regime has freed political prisoners.

No one would be surprised if all this seeming good news eventually melted away, as happened in 2004. Khamenei isn't any less hostile to U.S. interests now than he was then, and no one knows his endgame — good reason to respond with caution.

But there is a parallel danger to keep in mind as well: that those who benefit from perpetual U.S./Iranian hostility will kill the initiative even if it proves promising.

Rouhani will have his hands full trying to fend off the country's hard-liners. His decision to avoid a stage-managed encounter with Obama at the U.N. Tuesday signaled as much.

Obama, meanwhile, will have to contend with two allies — Israel and Saudi Arabia — who are eager to have the U.S. attack and press for regime change, which the president said he does not seek. They'll likely try to define anything short of total Iranian capitulation as failure, knowing that such an outcome is impossible.

Rather, the best hope is to get a verifiable agreement that Iran is abandoning its nuclear weapons program in exchange for the lifting of sanctions and the removal of any threat of attack.

Other sources of tension, notably Iran's support for terrorism, will need to be dealt with separately.

That can be seen as an unsatisfying half-loaf, like removing Syria's chemical weapons without ending its civil war. But it also would attain a top U.S. priority and avoid a very dangerous war — not an opportunity to be blithely turned away.

USA TODAY's editorial opinions are decided by its Editorial Board, separate from the news staff. Most editorials are coupled with an opposing view — a unique USA TODAY feature.