Meet MOP, who says, 'You can dig, but you can't hide from me.':
As U.S. concern about the nuclear ambitions of North Korea and Iran have grown, weapons designers have been working on bombs capable of destroying those countries' underground nuclear sites.
....The latest of these weapons is the MOP — short for Massive Ordnance Penetrator — built by Boeing's Advanced Systems unit in St. Louis. The 20-foot-long bomb that weighs 30,000 pounds — much heavier than the 21,000-pound MOAB, or Massive Ordnance Air Burst bomb, unveiled in the prelude to the Iraq war.
....The MOP was successfully tested earlier this month at White Sands, N.M. A Boeing handout last week made clear the weapon's likely targets:
"The weapon's effectiveness against hard and deeply buried targets allows the warfighter to hold adversaries' most highly valued military facilities at risk, especially those protecting weapons of mass destruction," said Bob McClurg, Boeing Advanced Systems MOP program manager.
At Wired magazine's defense blog, Danger Room, David Hambling says that the MOP has much more penetrating power than military's best current non-nuclear option, the 5,000-pound BLU-113, which can penetrate 22 feet of concrete:
MOP will go a lot deeper — 200 feet of 5,000 psi concrete. ....
The U.S. also has nuclear "bunker busting" weapons, in particular the B61-11, which was developed in the 1990s.