Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, raised the alarm yesterday over Iran's nuclear activities. In an interview with CNN, he said Iran "might now have enough fissile material to make a bomb." And a nuclear-armed Iran, he added, "is a very, very bad outcome for the region and for the world."

Secretary of Defense Robert Gates was also on the talk-show circuit. While he made a more cautious assessment ("They're not close to a weapon at this point," he told Meet the Press), the consensus is clear: Iran has not suspended work on uranium enrichment; it has been less than forthcoming about what it is up to; and we are worried about a "breakout" capability.

When my wife (and Danger Room contributor) Sharon Weinberger and I visited Iran in February 2007, the Iranians had produced 250 tons of uranium hexafluoride (UF6), a gaseous compound that could be fed into centrifuges for further enrichment through isotope separation. That same month, Iran began commercial-scale operations at an enrichment plant in Natanz; it continues to feed UF6 into a 3,000-centrifuge unit there.

So when do we start worrying? As this sober analysis in Time points out, almost 800 kilograms of low-enriched uranium has passed through the centrifuges at Natanz, and those stocks are monitored and under seal. For Iran to make a single, crude bomb, it would need highly enriched uranium. That would mean kicking out international inspectors, reconfiguring the cascades and re-enriching the low-enriched material. Experts reckon it would take months for that to happen, enough time for a dramatic international response. Even if successful in developing a Hiroshima-style device, Iran would not have anything that could be packaged on, say, a ballistic missile.

The Board of the International Atomic Energy Agency convenes this week in Vienna; in his introductory statement to the board of governors, IAEA director general Mohamed ElBaradei said the agency "was unable to make any progress on the remaining issues which give rise to concerns about possible military dimensions of Iran's nuclear program because of lack of cooperation by Iran." In other words, a lack of transparency is keeping the world guessing about Iran's true nuclear intentions. (The latest IAEA "safeguards report" is still being circulated internally, but if you feel like losing some sleep, you can check out the November 2008 IAEA board report.)

But the most crucial point, it seems, is the consensus within the U.S. military and intelligence community that Iran is on the path to nuclear weapons capability – even if it is still, as Gates suggested, a ways away from producing an actual bomb.

A 2007 national intelligence estimate concluded that Iran halted work on its covert nuclear weapons program in 2003, but that conclusion has now been consigned to the dustbin. The threat assessment delivered earlier this month by Dennis Blair, the Director of National Intelligence, puts it bluntly: "Although we do not know whether Iran currently intends to develop nuclear weapons, we assess Tehran at a minimum is keeping open the option to develop them."

The question, then, is this: What options are the United States and Israel keeping open?

[PHOTO: via NYTimes.com]

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