A bomb to bust the deepest bunkersDESPITE the intelligence failure that led the Bush administration to believe Iraq had weapons of mass destruction, the Pentagon is pressing ahead with the development of technologies designed to destroy WMDs. Its latest idea is a bomb that can destroy deeply buried WMD storage bunkers by cutting through earth and concrete inside a bubble of air. Traditional "bunker busters" are streamlined bombs that rely on sheer weight to force their way through soil, rock or concrete. But the new design has a blunt nose that forces the earth ahead of it out to the...