By Jerry Guo

The United Nations' inspection of Iran's clandestine nuclear facility outside Qum, slated as of press time for Oct. 25, was already treated as something of a coup in the West. With its air-defense batteries and centrifuges buried deep in the mountainside, the site smacked of dangerous nuclear intentions. But assuming the visit takes place, the progress it represents needs to be kept in perspective. By cooperating with the U.N., Mahmoud Ahmadinejad's regime gets to look as if it's opening a window on its nuclear program, slowing the momentum toward tougher international sanctions, when it's likely that Qum is only one of many secrets Iran is concealing. 

U.S. arms-control experts say that Qum is probably one of at least a half-dozen undeclared sites in Iran's "nuclear archipelago." At its present rate of production, Qum's estimated 3,000 antiquated IR-1 centrifuges would take two years to churn out enough highly enriched uranium for a single bomb, according to Gary Milhollin, director of the Wisconsin Project on Nuclear Arms Control. If Iran had another secret site, its parallel fuel cycle would cut down the waiting time to a year.

Furthermore, because Iran went to the trouble of hiding Qum, it's likely hiding other key components of a weapons program too. Take the conversion plant at Isfahan, which provides the uranium that goes into an enrichment facility--in this case, the site at Natanz. Both sites are being closely monitored by the International Atomic Energy Agency. The amount of uranium needed at Qum, some 7 to 16 percent of Isfahan's stockpile, would be too great a diversion to go unnoticed, says Andreas Persbo, an arms-control analyst at the U.K.-based Ploughshares Fund. 

The existence of Qum's secret enrichment facility thus implies a corresponding conversion plant, as well as mines to extract uranium ore, labs to turn the enriched fuel into a metal, and workshops to produce firing circuits and high-explosive ­lenses. Indeed, The New York Times recently reported that classified portions of the 2007 U.S. National Intelligence Estimate listed some dozen additional suspected nuclear sites in Iran. As the black sites multiply, chances are that Western intelligence agencies will not be able to keep tabs on all of them. It's a game of hide-and-seek that the West can't afford to lose.