Numbers

In its latest verbal barrage, Tehran claims that it is testing a new centrifuge, that would allow it to enrich uranium faster, and (presumably) develop a nuclear weapon sooner. But that assertion is difficult to verify; as with other elements of the Iranian nuclear program, the centrifuge issue is a question of numbers--and it's unclear if Tehran has the numbers to back up its claims.

In a speech to students last week, Iranian President Mamoud Ahmadinejad claimed that his country is now testing a type P-2 centrifuge, which reportedly has four times the capacity of the P-1 models now in operation. Tehran has displayed drawings of the P-2 in the past; it is believed that they obtained designs from the centrifuge from Pakistan's A.Q. Kahn proliferation network. However, there is no indication that the larger centrifuges have entered operational service. IAEA inspectors paid a visit to the Iranian enrichment facility at Natanz over the weekend; the centrifuges at that complex are believed to be the older, P-1 variety.

The global community is understandably nervous about Iran and its nuclear ambitions. Oil is now at $70 a barrel, and worries about potential conflict in the Gulf Region are likely to drive the price higher. Precious metals are also higher, largely on growing concerns about the Iranian nuclear issue.

But a little perspective is also in order. Enriching enough uranium to produce a working nuclear weapon is very much a numbers game. Want a bomb fast? Then you'll need a cascade of centrifuges--the more, the better. Based on the best information I can find, the cascade observed in Natanz over the weekend had only 164 centrifuges, and the output is at a level of about 3.5%--high enough to produce fuel for a nuclear power reactor, but not sufficient for short-term weapons development. For that type of work, an output level of 90%--or higher--is optimum. To develop sufficient material for a bomb over say, the next year, you need a huge cascade of roughly 54,000 centrifuges.

And you don't jump from a relatively small cascade to a huge array overnight. Over the weekend, I had an e-mail exchange with a former weapons inspector, with extensive experience on the Iraqi nuclear issue, and some insight into the Iranian program. The former inspector believes that Iran will have to operate a small-scale cascade for at least 6-12 months before ramping up production. Obviously, the availabilty of P-2 centrifuges would help, but there is no evidence that Iran has the larger models in quantity (yet).

This former inspector also opined that Iran may have only a limited supply of the parts required for building centrifuges, estimating that Tehran might be able to assemble another 1-2,000 over the next year. Even if those are the larger P-2 models (and that's a stretch), it's still a long way from the 50,000 needed for fast-track, weapons-scale enrichment efforts (with the P-1), or the 12-13,000 needed, if the P-2 models are used. Beyond that, Iran still has the issues of output and quality to contend with.

A cautionary note: I am not trying to underestimate the menace posed by Iran's nuclear program. But Tehran still has significant technical and logistical barriers to overcome to reach the production levels needed to build a bomb. When will they overcome those hurdles? That's the $64,000 question, but given current levels of activity, Iran's progression along the enrichment track would probably produce a weapon in the 2009-2010 timeframe, and not in 2006 or 2007.

Having said that, we must emphasize (again) that there are significant gaps regarding what we actually know about Iran's nuclear program. The lack of P-2 centrifuges at Natanz may suggest that those models are being used (or will be used) in a parallel program at a covert facility. If the secret effort is more advanced/producing enriched uranium on a larger scale, Iran could have the material for a bomb before 2009 or 2010. As we've noted on numerous occasions, the possibility of a "dual track" nuclear program in Iran cannot be dismissed.

Late last week, a senior Israeli official stated that the west had missed the opportunity to head off Iran's nuclear program. I'm not sure the window of opportunity has closed completely, but it is closing, and our time for decisive action is probably measured in months--not years.