Ken Dilanian: Iran is Pursuing Research, But has not sought to build a nuclear weapon.

As US and Israeli officials talk publicly about the prospect of a military strike against Iran's nuclear program, one fact is often overlooked: US intelligence agencies don't believe Iran is actively trying to build a nuclear bomb. A highly classified US intelligence assessment circulated to policymakers early last year largely affirms that view, originally made in 2007. Both reports, or national intelligence estimates, conclude that Teheran halted efforts to develop and build a nuclear warhead in 2003. The most recent report, which represents the consensus of 16 US intelligence agencies, indicates that Iran is pursuing research that could put it in a position to build a weapon, but that it has not sought to do so. Although Iran continues to enrich uranium at low levels, US officials say they have not seen evidence that has caused them to significantly revise that judgment. Senior US officials say Israel does not dispute the basic intelligence or analysis, but Israel appears to have a lower threshold for action than Washington. It regards Iran as a threat to its existence, and says it will not allow Iran to become capable of building and delivering a nuclear weapon. Some Israeli officials have raised the prospect of a military strike to stop Iran before it's too late. It's unclear how much access US intelligence has in Iran, a problem that bedeviled efforts to determine whether Iraq had weapons of mass destruction before the US led invasion in 2003.