Use of US bunker-buster bomb looms over Iran conflict

The GBU-57, a 30,000-pound (13,607 kg) warhead capable of penetrating 200 feet (61 meters) underground before exploding, is missing from Israel's arsenal despite its stated goal of preventing Iran from building a nuclear bomb. Why this bomb? In less than a week, the Israeli army has taken out Iranian military commanders and damaged numerous surface installations, raising more questions than answers. "The regime's missile stockpiles, launchers, military bases, production facilities, nuclear scientists...