ARI SHAPIRO, HOST:
For a generation of American spies, Iran has been one of the toughest targets in the world. The CIA was forced to close its station in Tehran when the U.S. embassy was taken over in 1979. And ever since, Iran has been an intelligence black hole. That won't change overnight, but with the recent nuclear deal, diplomats in Tehran and Washington are now in constant contact. NPR's Mary Louise Kelly reports that spy agencies are tracking the diplomatic developments with great interest, wondering what doors they may open for espionage.
MARY LOUISE KELLY, BYLINE: Here's one way to look at the challenge. Most CIA officers assigned to spy on Iran have never set foot in the country.
>>FADDIS I have never stepped across the border.
KELLY: Sam Faddis spent a career chasing secrets across the Mideast, eventually heading the weapons of mass destruction unit at the CIA's Counterterrorism Center.
SAM FADDIS: I worked both Iraqi and Iranian targets for a long time. The Iraqis were a very difficult target - the Iranians much more so.
KELLY: Faddis says that's partly thanks to extreme discipline on the part of Iran's security forces.
FADDIS: Their counterintelligence capabilities are very, very good. They're very smart. They're very organized. They're also absolutely ruthless.
KELLY: The single biggest handicap for spies like Faddis has been the lack of an embassy these last 30-plus years because in most countries, here's how it works. Intelligence officers operate under official cover, meaning they have a cover job attached to the embassy. If they get caught, they have diplomatic immunity. Paul Pillar, the CIA's former top analyst for the Middle East, says that's one reason Tehran may not rush to restore full diplomatic relations.
PAUL PILLAR: There will certainly be hesitation on the Iranian side not to open up something that they would start calling a nest of spies.
KELLY: A nest of spies - a reference to the American compound.
PILLAR: I think many Iranians, especially on that hard-line side, would be quite content to make it as hard as they can as long as they can for us to find out information about them.
KELLY: And even if - and it's still a big if. But even if the U.S. reopens its embassy at some point, Paul Pillar says it will still be incredibly tough for the CIA and other spy agencies to learn the things they want to know about Iran's regime.
PILLAR: Because they aren't secrets. They are unknowns for other reasons. What will be the political future in Tehran, the struggle between hard-liners and moderates? How will it come out the years ahead? That's something that isn't secret in somebody's head or someone's drawer for us to find out.
KELLY: John Limbert agrees. Limbert was one of the American diplomats held hostage in Iran after the revolution there. He served as President Obama's point man on Iran at the State Department. Limbert believes the greatest benefit of the current climate of diplomacy may simply be more American business travelers, more American journalists pouring into Iran. That makes it easier for American spies to blend in and move around and talk with ordinary Iranians.
JOHN LIMBERT: So how does the teacher in Esfahan or the social worker in Tabriz or the engineer in Tehran - you know, what's on their mind? What are they dealing with? In a way, that's more interesting and more revealing than, you know, what is Hashemi Rafsanjani thinking about?
KELLY: Rafsanjani, the former president of Iran - whether it's what's on his mind or the status of Iran's nuclear program, Paul Pillar says years of sifting through intelligence reports have taught him one thing.
PILLAR: The more contacts you have of any sort, official and unofficial, the better, be it - the better understanding you're going to have. And that's something we've certainly been lacking in Iran.
KELLY: Pillar adds, where there are diplomatic opportunities, intelligence opportunities almost always follow. Mary Louise Kelly, NPR News, Washington.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.