MELISSA BLOCK, host:
This is ALL THINGS CONSIDERED from NPR News. I'm Melissa Block.
ROBERT SIEGEL, host:
And I'm Robert Siegel.
This week, we're taking a close look at Iran's nuclear ambitions and the implications for U.S. policy toward Iran. To say the subject is complicated is an understatement. It involves questions of physics and chemistry, politics, diplomacy, the military and plenty of psychology. So, for the next few minutes, we're going to focus on just one question, the fundamental question of how close Iran might be to acquiring a nuclear weapon.
NPR's Mike Shuster reports.
MIKE SHUSTER: Listening to recent comments from Secretary of State Hillary Clinton, you might assume there's no doubt about it: Iran wants a nuclear weapon.
Secretary HILLARY CLINTON (Department of State): The world community is united in a rejection of Iran's pursuit of nuclear weapons. And we want to point out that it may not actually deliver the enhanced power that Iran believes it could.
SHUSTER: Iran's leaders deny they are seeking a nuclear weapon, but for years they pursued nuclear technology in secret. And even now they won't answer some key questions about their nuclear activities. The International Atomic Energy Agency keeps issuing reports tracking the growth of Iran's declared nuclear infrastructure. It is known that Iran has installed some 7,000 gas centrifuges at a facility at Natanz. These centrifuges are used to enrich uranium. And it is known that Iran has enriched uranium to a low level that could be used to fuel nuclear power plants but not be used in an explosive device. It's not a huge technical leap from low-enriched uranium to bomb-grade material, says Muhammad Sahimi, professor at the University of Southern California, who writes for the Web site Tehran Bureau.
Professor MUHAMMAD SAHIMI (Professor, University of Southern California; Writer, Tehran Bureau): Certainly, Iran has stockpiled enough low-enriched uranium that, if converted to high-enriched uranium, could be used for making one nuclear bomb.
SHUSTER: That most experts agree could be done in only a matter of months. But is that the most likely path Iran would choose to make a bomb? The U.S. intelligence community says no. Earlier this year, the director of national intelligence, Dennis Blair, told the Senate Select Committee on Intelligence that it would take Iran until about 2013 to acquire enough highly enriched uranium for a bomb. The intelligence community says Iran would not use its low-enriched uranium for that purpose. It's under seal and constant monitoring. If Iran diverted that for military purposes, the world would know immediately and that would put Iran in jeopardy, says Thomas Fingar, former deputy director of national intelligence and chairman of the National Intelligence Council.
Mr. THOMAS FINGAR (Former Deputy Director of National Intelligence): They would be telegraphing their intentions and making themselves much more vulnerable during that period, and therefore, a separate, secret effort was more likely.
SHUSTER: The U.S. intelligence community believes that if Iran's leaders decided they want a nuclear weapons capability, it would all be done in secret. They would build a secret centrifuge facility and use a separate supply of natural uranium to make low-enriched uranium, and then further enrich it to bomb-grade in secret. That could very well take four years or more. Gary Milhollin disagrees. Milhollin is the director of the Wisconsin Project on Nuclear Arms Control which maintains the Web site Iran Watch.
Mr. GARY MILHOLLIN (Director, Wisconsin Project on Nuclear Arms Control): I think that's wrong, because it makes a lot of assumptions that I don't think can be defended. The first one is that they would not divert the low-enriched uranium they already have. And second, that they would not be able to build a facility - even in secret - that could enrich enough uranium for a bomb in a year or two.
SHUSTER: If Iran decided to divert the low-enriched uranium it already possesses, Milhollin believes it would quickly acquire enough highly enriched uranium for a bomb.
Mr. MILHOLLIN: Iran could be as close as a few months or as long as a year or two away from making a bomb, depending on the assumptions you make.
SHUSTER: The U.S. intelligence community believes Iran's leaders have not made a final decision on whether to acquire a bomb. Muhammad Sahimi thinks that's an accurate assumption.
Prof. SAHIMI: This is basically a political decision at the highest level of Iranian leadership. And I don't think they will make the decision so long as they think that every move that they make is being scrutinized.
SHUSTER: The scrutiny from the IAEA, the U.N. Security Council and the U.S. in Europe has been effective. Iranian leaders have been reluctant to go for the bomb while they are under such scrutiny, says Thomas Fingar, who is now a scholar at Stanford University.
Mr. FINGAR: Iran would be unlikely to reverse that judgment as long as scrutiny and pressure continue.
SHUSTER: So, pressure should continue including engagement and diplomacy but not the constant threat to use military force, says Fingar.
Mr. FINGAR: I think the combination of carrots sticks, willingness to dialogue, to address in some way what Iran's security concerns are, undercuts a rationale for moving toward a weapon. Threats to use military action, I think, have a non-trivial possibility of reinforcing a judgment in Tehran that they need the ultimate deterrent.
SHUSTER: The point here is, how the United States acts toward Iran can affect how long it may actually take Iran to acquire a nuclear weapon.
Mike Shuster, NPR News.