U.S. intelligence agencies now suspect that Iran never halted work on its nuclear arms program in 2003, as stated in a national intelligence estimate made public three years ago, U.S. officials said.
Differences among analysts now focus on whether the country's supreme leader has given or will soon give orders for full-scale production of nuclear weapons.
The new consensus emerging among analysts in the 16 agencies that make up the U.S. intelligence community on Iran's nuclear arms program is expected to be the highlight of a classified national intelligence estimate nearing completion that will replace the estimate issued in 2007.
The unclassified summary of the 2007 document said the U.S. intelligence community had "moderate confidence" that Iran's nuclear weapons work had halted in 2003. In a footnote, it stated that weapons development was defined as warhead design and not the enrichment of uranium, which has continued unabated contrary to the Iranian government's agreement not to develop uranium enrichment techniques outside International Atomic Energy Agency controls.
A senior U.S. military officer who spoke on the condition of anonymity last week revealed that the new argument among analysts is over Iran's decision to move forward with weaponization.
"There is a debate being held about whether the final decision has been made. It is fair to argue that the supreme leader has not said, 'Build a nuclear weapon.' That actually does not matter, because they are not at the point where they could do that anyway."
The officer, who is knowledgeable about operational matters and intelligence on Iran, said Iran's nuclear program is well-advanced and moving toward the point at which a weapon could be built.
"Are they acting as if they would like to be in a position to do what the supreme leader orders if he gives the thumbs up at some point down the road? The answer to that is indisputably yes," the officer said.
Newsweek magazine first reported Saturday that the new estimate was being drafted and may be released as soon as next month.
The new estimate is under debate as the Obama administration seeks to gain international backing for more sanctions against Iran, and amid growing political opposition to the Tehran government from Iran's "green movement" in recent months.
Iran's government has repeatedly denied that its uranium enrichment is part of a nuclear weapons program.
The new estimate also is expected to update testimony by Director of National Intelligence Dennis C. Blair, who told Congress in March that Iran "has not decided to press forward" with work to put a nuclear warhead on a ballistic missile.
Since his testimony, however, Iran was forced to disclose a new parallel uranium enrichment facility near Qom after U.S. and allied intelligence agencies discovered the previously undisclosed site at a military base.
In addition, an internal document from the International Atomic Energy Agency made public last fall concluded that Iran at least had the know-how needed for weaponization, according to a report by the Associated Press.
The 2007 national intelligence estimate prompted harsh criticism from U.S. allies and some members of Congress and the Bush administration, who said the document had been "politicized" to undermine any policy that would authorize a military strike on Iran's nuclear facilities.
Rep. Peter Hoekstra, Michigan Republican and ranking member of the House Permanent Select Committee on Intelligence, said in an interview that "they wrote a political document in 2007 to embarrass President Bush which everyone uniformly agrees was a piece of trash."
The congressman added, "I am glad the intelligence community is redoing it. They were wrong in 2007 when they were doing it, they were wrong by a significant degree. Why would I take the one in 2010 they are doing any more seriously, just because I like the outcome?"
David Albright, president of the Institute for Science and International Security, also said the 2007 estimate was flawed. "I think the idea Iran has not restarted with moderate confidence, it is a little like debating whether the glass is half full or half empty. Moderate confidence does not mean much and many intelligence agencies, such as the ones in Britain, France and Germany, disagreed that the weaponization did not exist in 2007," Mr. Albright said in an interview.
Ross Feinstein, a spokesman for the Office of the Director of National Intelligence, declined to comment.
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