PETER KENYON, BYLINE: Nonproliferation experts are wondering if the end is near for a complicated piece of diplomacy that saw Iran significantly cut back on its nuclear program in return for sanctions relief. James Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace, says the signs aren't good.
JAMES ACTON: Well, the deal is not dead yet. But I think, realistically, it's not likely to survive very much longer.
KENYON: Other nonproliferation experts are taking a slightly more optimistic view. Laura Rockwood, longtime nuclear safeguards official with the IAEA, the International Atomic Energy Agency, now directs the group Open Nuclear Network in Vienna. She says, rhetoric aside, what Iran has actually done to date doesn't add up to a sprint to acquire nuclear weapons.
First, she says, Iran is still cooperating with IAEA inspectors. Second, Iran has also not threatened to pull out of another important agreement, the Nuclear Nonproliferation Treaty. Rockwood says her cautious optimism could change if Tehran starts enriching to a higher level of purity - say, to 20% or more.
LAURA ROCKWOOD: If Iran were to enrich uranium above 20%, which is considered high-enriched uranium - probably not high enough or weapons-grade, but it's more than what they need - that would send a very bad signal.
KENYON: At stake is a deal designed to stop Iran from getting a nuclear weapon for at least a decade. Rockwood says most of Iran's violations can still be reversed fairly easily. What would really set alarm bells ringing would be a move to stop allowing the inspectors to see what's going on at Iran's nuclear sites.
ROCKWOOD: Incredibly important - it's fundamental. If they were to choose to not cooperate with the IAEA, this would send an extremely bad message.
KENYON: The latest pressure on the deal came Wednesday from Europe. Britain, France and Germany announced they're invoking the deal's dispute resolution mechanism, which amounts to a formal accusation that Iran's breaching the agreement. That prompted Iran's supreme leader, Ayatollah Ali Khamenei, during his first Friday prayer sermon in eight years, to blast those European countries as enemies of Iran.
(SOUNDBITE OF ARCHIVED RECORDING)
SUPREME LEADER ALI KHAMENEI: (Non-English language spoken).
KENYON: "Today, everyone knows it clearly," he said. "After waiting for one year," Khamenei added, "it became clear that they, the Europeans, are actually servants of the U.S. - servants of the U.S." He repeated it for emphasis.
The European move could lead to more sanctions on Iran, which is what the U.S. wants. Meanwhile, the German defense minister has confirmed that the White House threatened its European allies with punitive trade tariffs if they didn't formally accuse Iran of violating the nuclear deal. Now they've done so, and they're waiting for Iran's response.
