U.S. spy agencies are considering whether to rewrite a controversial 2007 intelligence report that asserted Tehran halted its efforts to build nuclear weapons in 2003, current and former U.S. intelligence officials say.
The intelligence agencies' rethink comes as pressure is mounting on Capitol Hill, and among U.S. allies, for the Obama administration to redo the 2007 assessment, after a string of recent revelations about Tehran's nuclear program.
German, French and British intelligence agencies have all disputed the conclusions of the 2007 National Intelligence Estimate, or NIE, in recent months, according to European officials briefed on the exchanges.
Intelligence on the state of Iran's nuclear capabilities has for years been politically fraught within Washington and among U.S. allies and international institutions like the International Atomic Energy Agency.
Rewriting an NIE is a major undertaking because it is the most comprehensive of U.S. intelligence reports and reflects the combined judgment of all 16 American intelligence bodies.
The 2007 report created a political headache for the Bush administration when Republicans and some allied governments such as Israel criticized the broad public conclusion that Iran was backing off its nuclear ambitions.
The report reversed earlier findings that Iran was pursuing a nuclear-weapons program. It found with "high confidence" that Iran halted its nuclear weapons program in 2003, and with "moderate confidence" that it hadn't been restarted as of mid-2007.
So far, intelligence officials are not "ready to declare that invalid," a senior U.S. intelligence official said, emphasizing that the judgment covered the 2003-2007 time frame only. That leaves room for a reassessment of the period since the December 2007 report was completed, the official suggested.
The spy agencies "have a lot more information since we last did" a national intelligence estimate, the official said. Some of it "tracks precisely with what we've seen before," while other information "causes us to reassess what we've seen before," the official added.
If undertaken, a new NIE likely wouldn't be available for months. The U.S. and its allies have imposed an informal December deadline for Iran to comply with Western demands that it cease enriching uranium or face fresh economic sanctions.
A shift in the U.S. intelligence community's official stance -- concluding Iran restarted its nuclear weapons work or that Iran's ambitions have ramped up -- could significantly affect President Barack Obama's efforts to use diplomacy to contain Tehran's capabilities.
Any timeline for negotiations could be shortened if a new NIE concludes Tehran has restarted its atomic-weapons work, said officials involved in the diplomacy. But the White House could also use the new report to galvanize wider international support for sanctions against Tehran.
"Countries would no longer be able to hide behind the NIE," said a European official working on Iran.
U.S. intelligence officials have been discussing whether to update the 2007 NIE on Iran's nuclear capabilities, though no decision has been made yet on whether to proceed, a senior U.S. intelligence official said.
"At some point in the near future, our analytic community is going to want to press the reset button on our judgments on intent and weaponization in light of Qom and other information we're receiving," the senior intelligence official said, referring to Mr. Obama's recent revelation that Tehran was secretly assembling a uranium-enrichment facility at a military base outside the holy city of Qom.
Intelligence analysts have been plying the White House with shorter two- or three-page analyses on Iran, and Vice President Joe Biden's office and National Security Council officials have expressed interest in a new estimate, according to a person familiar with the matter.
Representatives for the director of national intelligence, the vice president and the NSC declined to comment.
In addition to the Qom disclosure, European intelligence services and United Nations inspectors have gathered new information pointing to a resumption of Iran's weapons work.
Germany's intelligence service, the BND, publicly challenged the U.S. NIE by disclosing information during a court case this year that pointed to ongoing Iranian nuclear-weapons work. The BND gave specifics on Iranian purchases of high-speed cameras and radiation detectors that could be used in testing atomic detonations.
A working paper composed by the IAEA, meanwhile, detailed evidence that Iran was continuing to experiment with nuclear warhead designs, according to people who have viewed it.
"The U.S. is being directly challenged by its closest allies" on Iran's weapons work, said David Albright, a former U.N. weapons inspector who heads Washington's Institute for Science and International Security and has viewed portions of the IAEA paper.
In the U.S., lawmakers in both parties are calling for new assessments.
"We need a much better intelligence picture of Iran," said California Rep. Jane Harman, who chairs the intelligence subcommittee on the House Homeland Security Committee and was the top Democrat on the House intelligence panel. Rep. Harman said intelligence officials should assume that the latest revelation of a secret enrichment facility may not be the only one, until they can disprove that assumption.