Ever since the U.S. and its partners finalized the nuclear deal with Iran in July, Secretary of State John Kerry has tried to downplay what diplomats call the possible military dimensions of Iran's nuclear program.
"We're not fixated on Iran specifically accounting for what they did at one point in time or another. We know what they did," Kerry said this summer. "We have absolute knowledge with respect to the certain military activities they were engaged in. What we're concerned about is going forward."
Even supporters of the deal, though, say Kerry was overselling that point. The U.S. believes that Iran experimented with nuclear weapons components in the past. But Iran has stonewalled international inspectors in the past and the U.S. does not have "absolute knowledge," according to a former Obama administration official, Robert Einhorn.
Congress plans to address the Iranian nuclear deal this month. Republicans in the House are expected to easily pass a resolution opposing the nuclear agreement. The Republican majority in the Senate is also against the deal, but Democrats could stage a filibuster. Even if both houses vote against the deal, they are unlikely to have the two-thirds majority in both chambers needed to override a veto by President Obama.
"What we know about past Iranian weaponization activities, we know from our own intelligence," Einhorn said. "We will have to make weaponization in Iran a top priority for U.S. national intelligence means going forward."
Einhorn, who is now with the Brookings Institution, says it was never in the cards that Iran would come fully clean on this question.
"It would be good if the Iranians made a full confession about their past nuclear work," he said. "They are not going to do that because it would contradict their narrative that they only have a peaceful program."
Einhorn doesn't see this issue as a critical deficiency of the deal.
Debating The Deal
But Harvard University's Olli Heinonin, a former top official at the International Atomic Energy Agency, disagrees. He says having full knowledge about the past will be crucial in the future — when Iran gets out from under the current limits on its nuclear program.
"You want to understand how far did they get," said Heinonin. "Then you know what else they need to do to manufacture a nuclear weapon."
Heinonin, speaking at the Foundation for the Defense of Democracies, which has been critical of the Iran deal, said knowing about the past will also help inspectors know where they should concentrate their efforts now.
He's also raising concerns about a recent Associated Press report that says there will be limits on what inspectors will be able to do at Iranian military sites.
"I think we create a precedent, really, how to deal with the sample-taking in Iran," he said. "There would be other places where you want to go, military sites. And if every time [it's] through some remote camera, where you are not controlling what you see, I don't think this is the way to do it in a credible manner."
A Short Timeline
The IAEA's director general, Yukiya Amano, says he's satisfied with the arrangements made with Iran. He's supposed to report on his findings by December, though Heinonen doesn't think that's possible.
"If you want to do a proper job, I think time is a bit short," Heinonin said.
On that point, Einhorn of the Brookings Institution agrees.
"I think it's inevitable that the December 15 report that Amano is supposed to produce will be inconclusive," Einhorn said. "I don't think there will be enough time. But more important than there not being enough time is that I don't think the Iranians will be cooperative enough to allow the file to be closed."
Einhorn said that may not be very satisfying to the critics, but he said there are ways to deter future weapons work by monitoring Iran closely and making clear there will be a response to any cheating.