VIENNA — Although international concern is growing about Iran's nuclear program and its regional ambitions, diplomats here say most U.S. intelligence shared with the U.N. nuclear watchdog agency has proved inaccurate and none has led to significant discoveries inside Iran.
The officials said the CIA and other Western spy services had provided sensitive information to the Vienna-based International Atomic Energy Agency at least since 2002, when Iran's long-secret nuclear program was exposed. But none of the tips about supposed secret weapons sites provided clear evidence that the Islamic Republic was developing illicit weapons.
"Since 2002, pretty much all the intelligence that's come to us has proved to be wrong," a senior diplomat at the IAEA said. Another official here described the agency's intelligence stream as "very cold now" because "so little panned out."
The reliability of U.S. information and assessments on Iran is increasingly at issue as the Bush administration confronts the emerging regional power on several fronts: its expanding nuclear effort, its alleged support for insurgents in Iraq and its backing of Middle East militant groups.
The CIA still faces harsh criticism for its prewar intelligence errors on Iraq. No one here argues that U.S. intelligence officials have fallen this time for crudely forged documents or pushed shoddy analysis. IAEA officials, who openly challenged U.S. assessments that Saddam Hussein was developing a nuclear bomb, say the Americans are much more cautious in assessing Iran.
American officials privately acknowledge that much of their evidence on Iran's nuclear plans and programs remains ambiguous, fragmented and difficult to prove.
The IAEA has its own concerns about Iran's nuclear program, although agency officials say they have found no proof that nuclear material has been diverted to a weapons program.
Iran's Islamist government began enriching uranium in small amounts in August in a program it says will provide fuel only for civilian power stations, not nuclear weapons.
On Thursday, the IAEA released a report declaring that Iran had expanded uranium enrichment and defied a Security Council deadline to suspend nuclear activities. In the meantime, the agency is locked in a dispute with Tehran over additional information and access to determine whether the program is peaceful.
In November 2005, U.N. inspectors leafing through papers in Tehran discovered a 15-page document that showed how to form highly enriched uranium into the configuration needed for the core of a nuclear bomb. Iran said the paper came from Pakistan, but has rebuffed IAEA requests to let inspectors take or copy it for further analysis.
Diplomats here were less convinced by documents recovered by U.S. intelligence from a laptop computer apparently stolen from Iran. American analysts first briefed senior IAEA officials on the contents of the hard drive at the U.S. mission here in mid-2005.
The documents included detailed designs to upgrade ballistic missiles to carry nuclear warheads, drawings for subterranean testing of high explosives, and two pages describing research on uranium tetrafluoride, known as "green salt," which is used during uranium enrichment. IAEA officials remain suspicious of the information in part because most of the papers are in English rather than Persian, the Iranian language.
"We don't know. Are they genuine, are they real?" asked a senior U.N. official here. Another official who was briefed on the documents said he was "very unconvinced."
Iran's representative to the IAEA, Ali Asghar Soltanieh, dismissed the laptop documents as "fabricated information." Iran, he said, has produced 170 tons of "green salt" at a uranium conversion facility in Esfahan that is monitored by the IAEA.
"We are not hiding it," he said in an interview. "We make tons of it. These documents are all nonsense."
The U.S. government is not required to share intelligence with the IAEA, and relations between Washington and the U.N. agency are at times testy. In March 2003, IAEA chief Mohamed ElBaradei embarrassed the White House when he told the U.N. Security Council that documents indicating Hussein's government in Iraq had sought to purchase uranium in Niger were forged. The Bush administration subsequently opposed ElBaradei's reappointment to his post.
While it confronts Iran's nuclear ambitions, the Bush administration also has tried to implicate Iran as a supplier of munitions and training for insurgent groups in neighboring Iraq.
But the quality of its information has limited this effort too.
U.S. officials recently compiled evidence purporting to show that the Iranian Quds Force, an elite unit of the Revolutionary Guard, had supplied Iranian-made weapons to Shiite militias that have attacked U.S. forces in Iraq.