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For some years now, people in national security circles have speculated about possible military strikes against Iran's nuclear program. The strikes have not yet happened but a quieter war is underway. It's involved cyber-attacks, assassinations and bombings, as well as defections. Some even argue that this covert war has become in effect the primary tool of U.S. policy toward Iran. NPR's Mike Shuster has the latest report in our series.
MIKE SHUSTER: For the United States, Iran is a hard case to crack. It figures prominently in so many foreign policy challenges for the U.S. - Iraq, Afghanistan, Israel and the Palestinians, and its own nuclear program.
For years, successive U.S. administrations have been at a loss to figure out how to change Iran's behavior. But in the past year, another option has emerged, says Karim Sadjadpour, an Iran specialist with the Carnegie Endowment for International Peace.
Mr. KARIM SADJADPOUR (Carnegie Endowment for International Peace): I think there's a perception that shunning Iran, ignoring Iran, is not an option. Bombing Iran or military engagement with Iran would exacerbate a lot of these challenges. And so the option we're left with is this kind of more creative in-between option of covert war and sabotage and economic coercion.
SHUSTER: Unlike the other approaches to Iran, the covert war, with the help of economic sanctions, has had some success. Last year, cyber-attacks and the computer virus known as the Stuxnet worm destroyed nearly a thousand centrifuges used to enrich uranium.
Other instances of sabotage have slowed down and for a short time stopped the uranium enrichment process entirely at Iran's key facility. Iranian scientists can no longer feel confident that the high-tech equipment they are buying on the international market is free of bugs or will work as it was designed to do.
Increasingly, these operations in the shadows are coming to be seen as the most effective approach, replacing more controversial and dangerous policies, says Muhammad Sahimi, a professor at the University of Southern California who writes for the website Tehran Bureau.
Professor MUHAMMAD SAHIMI (University of Southern California): Some people have pointed out to the success of this covert war as meaning that there is no need for overt military attack on Iran's nuclear program or other sensitive facilities because apparently these programs are having great success.
SHUSTER: There has been much discussion in the U.S. over the past five years about whether Iran is seeking to acquire a nuclear weapon - its leaders deny that - and what the benefits and costs might be of military action to prevent that from happening.
Covert action is providing a useful substitute for military action, says Paul Pillar, a former senior CIA official who now teaches security studies at Georgetown University.
Professor PAUL PILLAR (Georgetown University): To the extent it is an alternative to the use of military force, which has been of course talked up considerably in our country, it can be seen as a very helpful, non-bloody way of buying time and holding off pressure to use military force that would lead to a U.S. and Iranian war.
SHUSTER: One of the benefits of covert action is the confusion, paranoia and fear that these activities create among Iran's leaders, says Paul Pillar.
Mr. PILLAR: I expect they assume that the United States as well as Israel is responsible for a great deal of what is happening, whether or not they are indeed responsible.
SHUSTER: Covert operations also put great pressure on Iran's intelligence services to anticipate and counter them. In that respect, says Muhammad Sahimi, Iranian intelligence has fallen far short.
Mr. SAHIMI: The Iranian intelligence ministry, despite all its claims, hasn't done a good job in tracking down who, for example, was behind the assassination attempts of last year and explosions that were reported in some military bases and so on.
SHUSTER: And because covert ops are just that, secret, they are not saddled with a great disadvantage of military action - the likelihood that Iranians will close ranks around the current government in Tehran if the U.S. or Israel attacks, according to Karim Sadjadpour.
Mr. SADJADPOUR: The last thing the U.S. government wants to do is to take any measures that could prolong the shelf-life of the Iranian regime, to increase the popularity of the Iranian regime, and soil the oasis of goodwill which exists amongst the Iranian population vis-a-vis the United States.
SHUSTER: All and all, this is a far better way to handle the numerous challenges that Iran has presented the United States with for many years, says Bruce Riedel, formerly a CIA analyst now with the Saban Center at the Brookings Institution.
Mr. BRUCE RIEDEL (Brookings Institution): If we can delay the Iranian program, if we can upset Iran's terrorist activities through use of clandestine means, that's a far more effective and useful way of disrupting Iran's ambitions than having to send American forces into harm's way.
SHUSTER: This suggests that in the coming months there will be more stories emerging about cyber-attacks, defections, and about the occasional assassination and bombing as the clandestine war against Iran widens.
Mike Shuster, NPR News.