ABC characterizes Shahram Amiri as "an award-winning nuclear scientist" and says he worked at Tehran's Malek Ashtar University, which is closely connected to Iran's Revolutionary Guard and quotes an Iranian web site as saying that he worked at the Qom uranium enrichment facility that we first heard about last fall. Julian Borger calls Amiri "an expert on radioactive isotopes;" Juan Cole, "a consummate insider."
As several people have pointed out, Steven Walt among them, the absence of one scientist will have little or no effect on Iran's nuclear program. The big question is how much information Amiri brings to the US. From what I see, I simply can't tell what this might be. The radioactive isotopes Amiri is said to be expert on could be those used for medical treatments or they could be the fissionable kind.
Both ABC and Borger mention the revelation of the Qom facility last fall but fail to connect it in any substantive way to Amiri's defection.
ABC says that sources from the CIA "say Amiri helped to confirm U.S. intelligence assessments about the Iranian nuclear program." Of course he would be heavily questioned by the CIA, whatever his background. And was that confirmation that Iran ended its weapons program some years back?
At the same time, although I agree with Steve Hynd and Glenn Greenwald that there's more than a hint of bias in too much reporting on Iran, I can't ignore the game-playing by Iran in the capricious way it allows the IAEA access (and not) to its facilities. Juan Cole puts it carefully:
the International Atomic Energy Agency of the UN... continues to certify that none of Iran's nuclear material... being enriched for civilian purposes... has been diverted to military uses. The IAEA has all along said it cannot give 100% assurance that Iran has no weapons program, because it is not being given complete access.Unfortunately, the Qom facility is of a size that might be used as a finishing plant to bring partially enriched uranium up to bomb grade. And the story that there would be multiple plants for protection against strikes is less than convincing: they would be trucking cylinders of uranium hexafluoride around a country under attack?
The history of the Manhattan Project and of other nuclear programs in other countries show that the attitudes of scientists can vary greatly. Presumably a defector would be motivated to give a straight story.
But there are double agents...
I don't see any reason to believe that this defection makes a big difference. My guess is that there are a variety of opinions within Iran on the direction of the nuclear program and that we have yet to see which one wins out. In the meantime, we can hope that the Iranian to-ing and fro-ing doesn't convince anyone that the intentions are fully toward nuclear weapons. We can recall the misinformation in the United States about Saddam Hussein's weapons programs, but we must also recall Hussein's bluff that too many people really believed.