CBS News has learned that a new intelligence report says Iran has overcome technical difficulties in enriching uranium and could have enough bomb-grade material for a single nuclear weapon in less than three years.
U.S. intelligence officials caution that before Iran could meet or beat that 2010 date, it would have to make further technical progress in operating a uranium enrichment plant now under construction, reports CBS News national security correspondent David Martin.
As a result, there is no change in the official estimate that it will take Iran until 2015 to become a nuclear power. But David Albright, a leading expert, thinks that doesn't give Iranian scientists enough credit.
"I think Iran can get enough highly enriched uranium for a nuclear weapon sooner than that," Albright says. "I think the 2015 number reflects too much skepticism about Iran's technical capabilities, and they are making progress."
Although U.S. intelligence still considers an Iranian nuclear weapon by 2010 as a worst-case scenario, Pentagon officials say the new report narrows the window in which Israel might launch a preemptive strike against Iran, as it did in 1981 against an Iraqi nuclear reactor.
Israel is the country most threatened by the prospect of an Iranian nuclear weapon. Former CIA officer Bruce Riedel says this latest intelligence would increase the chances of an Israeli strike launched with American-built warplanes.
"The Israelis have long believed that Iran is closer than U.S. intelligence believes it is," Riedel says. "If they now hear that the Americans think it's getting closer as well, it puts pressure on Israel to take its own action."
Riedel adds that an Israeli strike would be seen in Iran as no different from an American strike and could involve the U.S. in a war against a much tougher opponent than Iraq.
In Tehran, CBS News correspondent Elizabeth Palmer reports the nuclear program is a matter of national pride.
A few weeks ago, president Mahmoud Ahmadinejad gathered reporters at the main nuclear plant in Natanz to boast that his country now could enrich uranium on an industrial scale.
But what exactly does that mean?
In the enrichment process, scientists feed uranium gas into linked centrifuges. Iranian officials hint that they have 3,000 centrifuges working at Natanz. But international atomic energy commission inspectors — who toured the plant last month — are reported to have seen less than half that many working — 1,300 — and only a few had uranium gas in them.
Iran insists its nuclear program is for peaceful purposes only — to make fuel for power plants being built in Iran by the Russians.
Two years ago, Palmer and her CBS News crew were the first Western reporters to be shown the heavy water plant at Arak, which the Iranians say is for making medical radioactive isotopes.
The trouble is few world leaders are convinced and at the moment there is no surefire way of checking until — perhaps — it's too late.