Although Iran maintains that its nuclear program is for peaceful energy purposes, Israel has long seen it as a threat. Israeli strikes have hit three of Iran’s nuclear facilities — Natanz, Isfahan and Fordow. Little damage appears visible in satellite imagery of Fordow.

Iran retaliated late Friday against Israel's attack on Iranian nuclear and military sites, raising concerns about an all-out war between the countries.

Iran's Supreme Leader Ayatollah Ali Khamenei said Israel “should expect severe punishment” for the attacks, which he said struck residential centers and killed several commanders and scientists. “The powerful hand of the armed forces of the Islamic Republic will not let them go unpunished,