How do you blast a hole through a mountain of concrete and granite and then blow up what hides beneath it―all without crossing the nuclear line? Since the Israel-Iran conflict broke out last week, much speculation has centered on this weapon: the GBU-57/B,

For days, Israel's military has been bombing Iran, its main target:  Iran's nuclear facilities. Israel is convinced that Iran is trying to build a nuclear weapon, an accusation that Iranian leadership has repeatedly rejected.