Ryan Mauro discusses the U.S. attack on Iranian nuclear sites at Fordow, Natanz, and Isfahan and what made them hard targets that only American bombs could reach and destroy. Each site had underground tunnels, including deeper tunnels at Natanz designed to withstand even American bombs. Iran will certainly retaliate but Iranian leadership will want to avoid going “too far” and provoke an American attack on Supreme Leader Ayatollah Ali Khamenei or his son.