Oct. 14 (Bloomberg) -- After a full decade of failure, the negotiations over Iran’s nuclear program, which begin again this week in Geneva, may have a better chance of being fruitful. The people involved are the same as before, and they have the same goals they always had. Now, though, some crucial facts have changed that may make both sides more realistic.

Most important, economic sanctions have taken a big toll on the Iranian economy, which is contracting amid a 40 percent inflation rate. Also, Hassan Rouhani’s surprise win in June’s presidential election made it clear to Iranian supreme leader Ayatollah Ali Khamenei that the sanctions have become a potential threat to his authority.

Although it’s still true that any nuclear deal would have to be approved by Khamenei, Mohammad Javad Zarif, Iran’s foreign minister, and Abbas Araghchi, Zarif’s lead negotiator, now appear to be getting down to specific issues more directly than before. This week, Araghchi pledged to “negotiate about the volume, levels and the methods of enrichment.”

Araghchi also said Iran wouldn’t agree to ship out any of its stock of 20 percent enriched uranium, yet that may be a demand that’s designed to trade away during talks and needn’t be a deal breaker. Once turned into fuel rods for use in a medical reactor, this material can no longer be made into fissile material for a bomb. The fuel could be secured while processed in Iran, given the correct safeguards.

On the Western side, things have changed, too. The U.S. and its European allies used to insist that no deal could include Iran continuing its uranium-enrichment program at all. After 10 years, it has become clear that the right to enrich really is a red line for Iran, as it is for the many emerging nations that have supported Iran’s position. U.S. and European (though not Israeli) diplomats appear now to recognize that the right to enrichment at the 3.5 percent level required for nuclear power plants will eventually have to be part of any deal.

What makes things more difficult than before is that Iran’s nuclear program is more technologically advanced than it was even two years ago, and has greater capacity -- so it is closer to giving Iranian leaders the option to “break out” and produce a bomb.

As a result, the talks in Geneva have to produce a complete but staged agreement, in which Iranian concessions are matched by meaningful sanctions relief. The outlines of a deal are rather clear: Enrichment to 20 percent must be stopped and the current stock neutralized; the capacity of Iran’s centrifuge-spinning enrichment operation must be limited to the needs of its sole nuclear power plant at Bushehr; all surplus infrastructure must be dismantled; Iran must volunteer to accept the maximum level of inspection and monitoring by the International Atomic Energy Agency; the heavy water reactor at Arak, due to come online next year, must be mothballed or placed under IAEA monitoring so intrusive that it amounts to control; and the bunker facility at Fordow must be either closed or subject to the same intensive monitoring.

There is no longer enough time to talk of “trust building.” The risk on both sides is that those who consider themselves to be steely-eyed skeptics of Iranian intentions, or diehard opponents of the Great Satan, will block a deal that doesn’t secure their maximum goals.

Trying to eliminate all risk that Iran will develop nuclear weapons is futile; airstrikes wouldn’t achieve this, either. A negotiated agreement should ensure that the time Iran requires to break out and make a weapon doesn’t become shorter -- and that in the event Iran’s leaders do make such an attempt, the rest of the world will know about it in time to act.

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