U.S. intelligence agencies have showed independence from the Bush administration with a skeptical assessment of Iran's nuclear capabilities that is far from the slam dunk case against Iraq before the war.

In a new National Intelligence Estimate, the agencies backed down from a 2005 assertion that Iran was determined to develop a nuclear weapon -- a conclusion cited by administration supporters of a hard-line policy against Iran.

Instead, the new estimate said Iran had a nuclear weapons program but froze it in 2003. It said we do not know whether Tehran currently intended to develop such weapons, and that at a minimum Iran was keeping its options open.

Senior intelligence officials said the report reflected lessons learned since an erroneous assessment on Iraq's weapons capabilities, and they said there was no political input.

There is no suggestion here of anything like a 'slam dunk' regarding Iranian nuclear weapons, said Stephen Aftergood of the Federation of American Scientists.

The intelligence community is publicly demonstrating its independence, and showing that it is far from being a cheerleader for military intervention, he said.

Democratic Sen. John Rockefeller, head of the intelligence committee, said the Iran findings represented a clear departure from the view expressed by top Bush administration officials.

This demonstrates a new willingness to question assumptions internally and a level of independence from political leadership that was lacking in the recent past, he said.

By contrast, a 2002 intelligence estimate, which concluded Iraq had chemical and biological weapons and was developing a nuclear weapon, was widely criticized as resulting from administration pressures to justify war against Iraq.

Then-CIA director George Tenet told U.S. President George W. Bush before the war that the case for Iraqi weapons was a slam dunk -- a quote Tenet says was reported out of context. No weapons stockpiles were ever found.


Director of National Intelligence Michael McConnell had planned to keep the new Iran findings secret. But intelligence agencies decided to declassify portions once it became clear the assessment had changed significantly from 2005.

That judgment (from 2005) has become part of a public policy dialogue about Iranian nuclear weapons. As we finished our conclusions these past few weeks, we determined it necessary to publicly update our assessment on that, a senior intelligence official said.

But officials declined to characterize the earlier assessment as a mistake. The fact that we appear to have missed a secret or covert program in 2005 when we had a paucity of data, and got more information subsequently ... is just part of the business, one official said.

Said another, Iran ... is probably the hardest intelligence target there is. In comparison, North Korea is an open and transparent society.

The officials said that for the new report they re-examined all their previous intelligence on Iran's nuclear programs and applied significant amounts of new information.

This included open source material from the International Atomic Energy Agency and news photos taken during a media tour of Iran's Natanz nuclear facility.

Some conclusions were presented with alternatives.

For example, the Department of Energy and National Intelligence Council were reported to have less confidence that Iran had halted its entire nuclear weapons program.

Furthermore, analyses were subjected to more challenges and alternative interpretations. This was a consequence of lessons learned and the new leadership, an official said.

Tenet resigned in June 2004 and the current director, Air Force Gen. Michael Hayden, was sworn in in May 2006.

A 2004 law created the Office of Director of National Intelligence as the top intelligence position. McConnell took his post last February.

Jon Wolfsthal of the Center for Strategic and International Studies said the Iran report contained a major element the 2002 Iraq report lacked -- its findings that outside pressure and scrutiny had led to a halt in the Iran's nuclear weapons program.

This is the piece of evidence that was missed in the case of Iraq, where the Bush administration was convinced that Iraq's efforts were continuing despite sanctions, he said.

(Editing by Patricia Wilson and Cynthia Osterman)