A Thaw in Geneva?

Talks in Geneva this week have reinforced the hope that Iran and the major powers — the United States, Britain, Russia, France, Germany and China — may finally be serious about resolving the long-running dispute over Iran’s nuclear program.

The negotiations were a start on what could be a productive conversation — but only a start.

On the plus side, Iran offered its own proposal to resolve the nuclear issue, complete with PowerPoint presentation. It had previously resisted putting forth specific ideas until international sanctions were lifted. That no significant official details of the discussions have emerged so far could actually be a positive sign. It suggests that, for now at least, the participants see value in giving serious consideration to what has been put on the table instead of trying to sabotage it with strategically placed leaks.

In another positive development, American and Iranian negotiators met privately for about an hour. Iran had rejected previous administration requests for this kind of direct exchange, which is needed if the two sides are to reduce the enormous mistrust that has built up over 30 years. The phone call last month between Hassan Rouhani, Iran’s more moderate president, and President Obama broke the ice and opened the way for this private, bilateral session as well as an earlier meeting between Mohammad Javad Zarif, the Iranian foreign minister, and John Kerry, the secretary of state.

It was also encouraging that the major powers and Iran ended the Geneva meeting with a rare joint statement praising Iran’s proposal as an “important contribution.” They also agreed to another negotiating session in three weeks, after their technical experts on nuclear, scientific and sanctions issues meet to discuss their differing approaches and develop practical steps to a deal.

There were also upbeat remarks from American and European officials, who described the talks as substantive and forward-looking. It would be foolhardy, however, to ignore the more sober note from Russia’s deputy foreign minister, Sergei Ryabkov, who said on Wednesday that the two sides are far apart and that there was no guarantee of further progress.

The gulf between them on the nuclear issue has been wide and deep for a long time. The major powers have demanded that Iran stop enriching uranium to 20 percent — a purity that makes it easier to produce fuel for a nuclear weapon; reduce its uranium stockpiles; subject its nuclear program to greater international scrutiny; and take other steps to prove it is not building weapons.

Mr. Rouhani and his aides have repeatedly asserted that Iran has no intention of producing weapons, but the country’s history of hiding its program, in whole or in part, requires strict limits and monitoring.

A certain patience is needed to conduct these negotiations and bring them to a constructive end. But hard-liners are already trying to undercut them. Prime Minister Benjamin Netanyahu of Israel, for instance, is warning against trusting Iran while members of Congress are threatening new and harsher sanctions. An early and tangible sign of good will — like a temporary freeze in Iran’s enrichment activities and some sanctions relief by the major powers — could begin to persuade both sides that real progress is possible.