'Now, after days of Israeli airstrikes, US intelligence officials believe that so far, Israel may have set back Iran's nuclear program by only a matter of months, according to one of those people, a US official.

Even as Israel has done significant damage to Iran's facility at Natanz, which houses centrifuges necessary to enrich uranium, a second, heavily fortified enrichment site at Fordow has remained effectively untouched.

Israel lacks the capability to damage Fordow without specific US weapons and aerial support, defense experts say.

"Israel can hover over those nuclear facilities, render them inoperable, but if you really want to dismantle them it's either a US military strike or a deal," said Brett McGurk, a former top diplomat to the Middle East under the Trump and Biden administrations and a CNN analyst.'