MELISSA BLOCK, HOST:
We turn now to Iran, where it's never been easy trying to figure out just what's going on inside its borders. But it's been especially difficult of late. An explosion reduced a missile base to rubble, another blast was heard but not seen and then there's the case of the American stealth drone that was mysteriously downed. As NPR's Mike Shuster reports, these episodes have left a slew of questions and very few answers.
MIKE SHUSTER, BYLINE: The missile explosion a month ago was huge. It was heard in Tehran about 30 miles away, and satellite pictures show it devastated the base. The second explosion came late in November, somewhere in or near Isfahan. It was heard all over the city and the local fire department went on alert. But there's no evidence of destruction. And the American surveillance drone, why was it lost and how did the Iranians end up with it? Lots of questions, says Nader Hashemi, an Iran analyst at the University of Denver.
NADER HASHEMI: No one really knows the true nature of why these explosions and why these events have happened.
SHUSTER: The explosion at the missile base killed several dozen people, including one of Iran's top generals who headed the country's missile program. Analysts who specialize in reading satellite photos have looked at the pattern of destruction, and wondered what explosive materials were present, and how they were detonated. Some have speculated that the devastation could have been sparked by an attack from the air, but there's no evidence of that.
Iran would only say it was an accident, and that's how Muhammad Sahimi sees it. He's a professor at the University of Southern California and writes for the website Tehran Bureau.
MUHAMMAD SAHIMI: There is this culture of carelessness and at the same time inexperience. In my view - although I have seen reports that Israel, for example, may have had a hand in creating the explosion, but in my view, the most likely cause of it was an accident.
SHUSTER: The second explosion occurred in Isfahan and the immediate thought was, did something explode at the uranium conversion facility outside the city? This is one of Iran's most important nuclear sites, producing a critical precursor of enriched uranium. The blast was first reported on one official website, then it was removed with no explanation. Since then, only silence.
And then, the mystery of the drone, a CIA asset based in Afghanistan. The Americans lost control of it and it ended up on Iranian TV last week. The Iranians claim they seized control of it electronically. There's no doubt it is an American drone. President Obama confirmed that on Monday.
PRESIDENT BARACK OBAMA: As has already been indicated, we have asked for it back. We'll see how the Iranians respond.
SHUSTER: What was it doing? It's a surveillance drone, capable of staying in the air for many hours. It was flying over eastern Iran, it appears, and that raises a suspicion in Mohammad Sahimi's mind.
SAHIMI: I think they are looking for what they suspect to be secret nuclear facilities. That's why the drone was where it was there.
SHUSTER: Iran's seizure of the drone has been trumpeted by its media as an intelligence coup. But the official explanation is puzzling, says journalist Omid Memarian.
OMID MEMARIAN: Many in Iran, they don't believe that the Iranian defense system is that sophisticated to target such a complicated and advanced spy aircraft.
SHUSTER: Iran watchers like Nader Hashemi believe Iran's leaders, too, have their own set of questions and are confused and fearful about what is going on.
HASHEMI: They are deeply disturbed by this and the general sense within the ruling clerical elite is that these events have been instigated from abroad.
SHUSTER: So even though the most likely explanations may be the simplest, there are reasons to go beyond simple answers, says Ali Vaez, head of the Iran project at the Federation of American Scientists.
ALI VAEZ: This can very well be the result of an accident, but it also looks like it's a concerted effort to push back Iran's nuclear weaponization program.
SHUSTER: Some might wonder, is a covert war is already under way in Iran? Mike Shuster, NPR News.