Israel has struck a blow to Iran's nuclear program—but it isn't yet a knockout

Israel has delivered a powerful blow to parts of Iran's nuclear program, but it hasn't yet taken out the most heavily protected of Iran's nuclear sites, leaving Tehran a potential path to the bomb.

- Laurence Norman, Michael R. Gordon & Dov Lieber

By Sunday, three days into its campaign, Israel had knocked out centrifuges at Iran's biggest enrichment facility at Natanz, killed up to 10 of the country's top nuclear scientists and destroyed key pieces of the supply chain for building a bomb, according to Israeli and U.N. atomic agency officials.

The course of Israel's military campaign will determine whether it can achieve a goal it has sought for decades—neutralizing Iran's nuclear program or setting it back years. Falling short carries great risk, possibly prompting Iran to kick out international inspectors and accelerate its efforts to build an atomic bomb.

Israel's biggest challenge remains: taking out Iran's most fortified nuclear facility, Fordow, where Iran produces highly enriched uranium. Many believe Fordow, which is built deep into a mountainside near Iran's holy city of Qom, could only be destroyed with a massive bunker-busting U.S. bomb.

"Israel thus far has targeted important parts of the Iranian nuclear program. But if you are worried about a nuclear breakout, Fordow is the game," said Richard Nephew, who served as a negotiator with Iran during the Biden and Obama administrations.

Still, the damage to Iran's nuclear program that Israel has already achieved is considerable. The International Atomic Energy Agency said the sudden loss of power at Natanz may have destroyed some of the roughly 14,000 underground centrifuges. The long cascades of centrifuge machines, which spin to produce uranium, are fragile and can break if they aren't shut down gradually.

An Israeli official said there were indications that the underground portion of the Natanz facility may have imploded, though he cautioned that additional assessments were needed.