I’ve never asked, but am willing to bet that the good folks at The Bulletin get a fair bit of grief over the Doomsday Clock. Seeing as we’ve been at five minutes to midnight since 2007 (the typical snide question presumably goes) just how it is that the world keeps turning?

That’s the problem with having a deterministic thing like a clock symbolize a probabilistic notion like risk. Either way, trying to shake people out of their complacency is a pretty good way to draw charges of sensationalism. Sometimes with justice. Sometimes not.

This brings us to Gal Beckerman’s analysis of the Iran nuclear clock in the Forward:

[E]arlier this month, it was revealed that the State Department’s Bureau of Intelligence and Research’s [INR] latest estimate has pushed that dreaded date back to 2013, when it posits that Iran will finally be able to produce highly enriched uranium [HEU], a key ingredient in any nuclear weapon…

What some see as the fine point of when exactly Iran gets the bomb is not inconsequential. The time frame for both diplomacy and a military response that would have serious ramifications hinge on this question. It is for this reason, a wide range of independent observers agree, that politics has played the most central role in how intelligence on Iran and its nuclear program is interpreted and packaged for the public.

“Clearly the fact that some of these assessments seem to change rather rapidly has fueled the suspicion that much of it is actually politically motivated,” said Trita Parsi, president of the National Iranian American Council.

Let’s not dwell on the fussy stuff, like the existence of fissile material other than HEU, INR’s position being a dissent from an Intelligence Community (IC) consensus, or this particular conclusion’s origins in the 2007 National Intelligence Estimate (NIE), not the April 2009 Questions for the Record (QFR) that Beckerman is thinking of. That would be, you know, fussy. Instead, let’s try to clarify a few key concepts.

First, what do these dates represent? Do they tell us “when exactly Iran gets the bomb,” as Beckerman puts it?

No. These dates refer to when Iran “probably would be technically capable of producing enough HEU for a weapon,” in the words of the 2007 NIE Key Judgments. Not when it will do so. This is a rather important distinction. Just for example, something we do learn from the 2009 QFR is that INR, at least, doesn’t think Iran is terribly likely to pursue this course. But that’s a topic for another blog post.

The bottom line is, it would be a mistake to imagine that we are destined to wake up one day between 2010 and 2015 (IC consensus) or between 2013 and 2015 (INR’s view) to learn of an Iranian nuclear test. Or at least, that’s not what the estimate conveys.

Second, is there any rational basis for these numbers? Aren’t they just plucked out of the air, as some would have us believe?

Documents are the greatest things. When you read them, you get information about stuff. Like what’s in the documents. In the 2007 NIE, it says:

We assess with moderate confidence that Iran probably would use covert facilities—rather than its declared nuclear sites—for the production of highly enriched uranium for a weapon.

And the recent QFR explains that INR thinks this capability is unlikely to be realized before 2013 because “Outfitting a covert enrichment infrastructure could take years.”

Now we know.

Third, why do estimates of when Iran will be able to produce fissile material tend to slide to the right as time passes? Isn’t it just a matter of serial sensationalism?

Some of the rhetoric of senior officials in the U.S. and Israel could be explained in those terms. But changes in more considered estimates like the NIE are probably better explained in terms of two other things: A) Having progressively more insight into the Iranian program and the difficulties it faces, which allows some easing back from worst-case estimates, and B) Changes in the facts themselves.

What sort of facts have changed in the last few years? Most obviously, Iran’s work on centrifuges was suspended for a couple of years, ca. 2004 to 2006. Little visible headway was being made at that time. More subtly, perhaps, some obstacles seem to have been thrown in Iran’s path along the way, especially since the end of that suspension. There are many examples of stories to this effect. Just look around...

All these matters are, I think, reasonably clear upon examination. But let’s entertain no illusions that reporters will stop tripping over them anytime soon.