More Details on What the U.S. Knows About Iran's Secret Nuclear Site

A U.S. counterproliferation official tells NEWSWEEK that intelligence agencies have been tracking the construction of this secret Iranian facility, built inside a mountain, for a matter of years. It is not finished, and the earliest they think it could become operational is a year from now or longer. One of the main reasons that President Obama, along with British Prime Minister Gordon Brown and French President Nicolas Sarkozy, felt it was appropriate to talk about it now is that Iran for the first time acknowledged the facility to the International Atomic Energy Agency earlier this week.

Another reason they may have decided to confirm the site's existence now is to get the story out before the Iranians circulate their own spin—which could be that this place is a pilot research facility. To U.S. and other Western officials, what's striking about the facility is its size: it's estimated to have the capacity to hold 3,000 centrifuges. The reason the U.S. and other countries think the facility is probably intended for producing highly enriched uranium for weapons is that it is too small to enrich the large quantities of uranium needed for a civilian power program, a U.S. counterproliferation official tells NEWSWEEK.

The official adds that the disclosure of the secret enrichment facility does not for the moment alter other judgments by U.S. intelligence agencies, including the conclusion, reported by NEWSWEEK earlier this month, that Iran has not restarted a program to specifically develop a nuclear bomb. U.S. agencies believe Iran was working specifically to develop a bomb until 2003, but then stopped its work on that program and has not resumed it. However, U.S. officials have always maintained that mastering the enrichment of uranium is the most difficult process in building a nuclear bomb, and many officials also believe that Iran may have acquired enough additional technology to put in place a kind of standby bomb-development program that could be rapidly restarted if a decision were taken to do so.

UPDATE: 

The secret enrichment facility is understood to be located on a military base near the holy city of Qum, according to a U.S. counterproliferation official. Iran is already making excuses for why it did not disclose the facility's existence earlier, to the public or to international nuclear regulators at the IAEA. In Tehran's view, international regulations do not require it to disclose the existence of such a facility until six months before nuclear material is going to be used in it. This interpretation of international standards is not shared by the U.S. and its allies.

A European diplomatic source says the disclosure of the secret Iranian project is certain to add urgency to international discussions regarding possible new sanctions against Iran. The first move to step up such sanctions would probably involve Western efforts to place new restrictions on financial transactions and trade with Iran, including drastic curbs on the sale to that country of equipment used to refine crude oil into gasoline. (Less likely, at least in the near future, would be Western sanctions curbing the sale of refined gasoline to Iran, a concept that some U.S. anti-Iran activists are promoting.)