A billboard showing a variety of missiles in Tehran last year. The Pentagon’s chief spokesman said on Thursday that Iran’s nuclear program had likely been degraded by one to two years by U.S. and Israeli bombing.
Credit...Arash Khamooshi for The New York Times

Pentagon Again Shifts Assessment of Damage to Iran’s Nuclear Program

The appraisal that Iran’s nuclear hopes had been set back 1 to 2 years by U.S. and Israeli bombings was the latest in a shifting series of pronouncements.

by · NY Times

The Pentagon’s chief spokesman, Sean Parnell, said on Wednesday that American and Israeli bombing campaigns set back Iran’s nuclear program by one to two years, the latest in a confusing series of shifting assessments of the damage the bombs inflicted on Iranian nuclear facilities.

Earlier this week, the chief United Nations nuclear inspector said that Iran could be enriching uranium again in a “matter of months,” even as President Trump continued to insist that the bombing had obliterated Tehran’s nuclear program.

Mr. Parnell said that U.S. allies were buoyed by the latest assessment.

“What we’ve seen, almost, in fact, just universally among our allies, is them congratulating the United States, the president, the secretary of defense, on that bold operation, and the idea that American action in Iran has set the conditions for global stability,” he said.

Iran’s president, meanwhile, has enacted a law to suspend cooperation with the United Nations’ nuclear watchdog, Iranian state media reported Wednesday, in a move that will shut out international inspectors from overseeing the country’s contested nuclear program.

American B-2 bombers hit two Iranian nuclear sites with massive “bunker buster” bombs last month, as Mr. Trump joined Israel’s bombing campaign in Iran. The Air Force dropped 12 of the massive GBU-57 bombs on the Fordo nuclear site and two on the nuclear site at Natanz. Mr. Trump has since declared a cease-fire and said that he was pursuing diplomacy with Tehran.

The issue of how far back the American and Israeli bombing campaign put the Iran nuclear program became almost an instant matter of contention, after Mr. Trump announced in the immediate aftermath of the American strikes that the bombs had “obliterated” Iran’s nuclear program.

Intelligence assessments since then, including ones by the Pentagon and the American intelligence community, have been more cautious. A preliminary assessment by the Defense Intelligence Agency that was widely reported on last week estimated that the strikes set back the Iranian nuclear program by only a few months. The C.I.A. director said later in the week that the Iranian program had been severely damaged, and the U.S. intelligence agencies were continuing to assess the strike.

Mr. Parnell was not presenting a formal Defense Department battle damage assessment on Wednesday. Defense Secretary Pete Hegseth Secretary last week echoed Mr. Trump’s language, and said, according to a White House statement, that “based on everything we have seen — and I’ve seen it all — our bombing campaign obliterated Iran’s ability to create nuclear weapons.”

But Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, has used more careful language, saying that “initial battle damage assessments indicate that all three sites sustained extremely severe damage and destruction.”

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