The conflict between Iran and the West just keeps heating up, with the Iranians announcing over the weekend that they have begun to enrich uranium at a second major facility, a well-defended site outside the city of Qom.

Given the high stakes, it's valuable to take another look at the main source of the tension: Iran's nuclear-weapons program. That this enterprise is active is widely considered a given in the United States.

In fact, the evidence, contained in a November report of the International Atomic Energy Agency, is sketchy. And the way the data have been presented produces a sickly sense of déjà vu.

I am speaking up about this now because, as a member of the IAEA's Iraq Action Team in 2003, I learned firsthand how withholding the facts can lead to bloodshed.

Having known the details then, though I was not allowed to speak, I feel a certain shared responsibility for the war that killed more than 4,000 Americans and more than 100,000 Iraqis.

A private citizen today, I hope to help ensure that the facts are clear before the United States takes further steps that could lead, intentionally or otherwise, to a new conflagration, this time in Iran.

It's accepted that Iran at one time had a nuclear-weapons program.

The country's enormous investment in a secret underground uranium-enrichment complex in the city of Natanz is essentially proof of clandestine intentions. The military plutonium-production reactor in Arak is yet another indicator.

However, it must be remembered that in the 2007 National Intelligence Estimate, U.S. agencies concluded that Iran halted its nuclear-arms program in 2003 under international pressure.

It's rare for intelligence officials to determine that they have sufficient evidence to say a program has ended, so their information presumably was very good.

Similarly, until this year, the IAEA had consistently reported that it had no information suggesting Iran had a nuclear-weapons program after 2004.

So the issue is not whether there is evidence of such a program, but whether there is evidence that it was restarted after being shut down in 2003.

The Nov. 8, 2011, report of the IAEA, under the leadership of Director General Yukiya Amano, is long on the former and very short on the latter.

In the 24-page document, intended for a restricted distribution but widely available on the Internet, all but three of the items that were offered as proof of a possible nuclear-arms program are either undated or refer to events before 2004.

The agency spends about 96 percent of a 14-page annex reprising what was already known: that at one time there were military dimensions to Iran's nuclear program.

What about the three indications that the arms project may have been reactivated?

Two of the three are attributed only to two member states, so the sourcing is impossible to evaluate. In addition, their validity is called into question by the agency's handling of the third piece of evidence.

That evidence, according to the IAEA, tells us Iran embarked on a four-year program, starting around 2006, to validate the design of a device to produce a burst of neutrons that could initiate a fission chain reaction.

Though I cannot say for sure what source the agency is relying on, I can say for certain that this project was earlier at the center of what appeared to be a misinformation campaign.

In 2009, the IAEA received a two-page document, purporting to come from Iran, describing this same alleged work. Mohamed ElBaradei, who was then the agency's director general, rejected the information because there was no chain of custody for the paper, no clear source, document markings, date of issue or anything else that could establish its authenticity.

What's more, the document contained style errors, suggesting the author was not a native Farsi speaker. It appeared to have been typed using an Arabic, rather than a Farsi, word-processing program. When ElBaradei put the document in the trash heap, Britain's Times newspaper published it.

This episode had suspicious similarities to a previous case that proved definitively to be a hoax. In 1995, the IAEA received several documents from the Sunday Times, a sister paper to the Times, purporting to show that Iraq had resumed its nuclear-weapons program in spite of all evidence to the contrary.

The IAEA quickly determined that the documents were elaborate forgeries. There were mistakes in formatting the documents' markings, classification and dates, and many errors in language and style indicated the author's first language was something other than Arabic or Farsi.

Inspections in Iraq later in 1995 confirmed incontrovertibly that there had been no reconstitution of the Iraqi nuclear program.

I regret now that ElBaradei did not speak out more vehemently, before the United States went to war, about the 1995 faked documents, additional forgeries provided to the agency in 2003 and other falsifications.

A good man, he had been an international lawyer with years of experience dealing with half-truths and prevarications. But he was trapped between telling the whole story and overtly insulting the United States, which supplied 25 percent of the IAEA's funding.

I should be clear: Iran deserves tough scrutiny. It claims to have given up its nuclear-weapons ambitions, yet repeatedly acts as if it has something to hide. I am a skeptic; I suspect the Iranians may have an ongoing weaponization program. And the uncertainty must be resolved.

At the same time, we should not again be held hostage to forgeries and the spinning of data to make the worst case. If Iran is developing nuclear weapons, let it be proved through the analysis of current, solid information -- not recycled, discredited data.

If there is to be a war with Iran, let's not have a repeat, afterward, of the anguished articles and books from officials who kept their misgivings to themselves. Let's get all the facts on the table now.

* * *

Robert Kelley, a nuclear engineer, was a director at the IAEA, where he worked for nine years. He gained his weapons expertise over 30 years at the University of California's nuclear-weapons laboratories. He wrote this article for Bloomberg News.