The UN nuclear agency responsible for probing whether Iran has worked on a nuclear bomb depends on the United States and its allies for most of its intelligence, complicating the agency's efforts to produce findings that can be widely accepted by the international community.
Much of the world looks at US intelligence on weapons development with a suspicious eye, given American claims a decade ago that Iraq had developed weapons of mass destruction.
The US used those claims to justify a war; Iraq, it turned out, had no such weapons.
The International Atomic Energy Agency insists that it is objective in evaluating Iran's nuclear program and that its information comes from a wide range of sources and is carefully vetted. But about 80 per cent of the intelligence comes from the United States and its allies, The Associated Press has been told.
Two IAEA officials, who gave the 80 per cent figure, told The AP that the agency has been forced to rely more and more on information from Iran's harshest critics the US, Israel, Britain, France and Germany because Tehran refuses to cooperate with international inspectors.
Their evaluation appeared to be the first in percentage terms. The officials demanded anonymity because they are not authorised to release classified information.
All five nations accuse Iran of having worked on nuclear arms, with Israel and the US not ruling out force as a last resort if diplomacy fails to curb programs that Tehran could use for such weapons.
France and Germany refrained from joining the Iraq invasion, insisting US intelligence about Saddam Hussein's purported weapons program was inconclusive.
Intelligence services of other nations, such as Pakistan, China or Russia, also collect information on Iran. But they are compromised by the fact that their governments or individuals provided the equipment or knowledge in the past that allowed Iran to develop its nuclear program.
Today, they are reluctant to pass on what they know to the agency for political reasons they want to be viewed as above the fray. They also view the IAEA more as technical organisation and less as the UN's nonproliferation watchdog, a role the agency has increasingly assumed with its Iran probe. That leaves the US and its allies as the IAEA's main intelligence sources.
Critics invoke the Iraq fiasco to warn that the information on Iran provided by Tehran's adversaries may be at best inaccurate and at worst spin, meant to pave the way for possible attack.
"Memories of the failure and tragic mistakes in Iraq are not taken sufficiently seriously," Hans Blix, a former IAEA chief, told reporters in Dubai in March.
"There is no evidence right now that suggests that Iran is producing nuclear weapons," said Blix, who headed the team that combed Iraq in the vain search for weapons of mass destruction.
