...he said the Defense Department was looking at a range of means -- including perhaps small nuclear bombs called "earth penetrators" -- to destroy or incinerate arms and facilities that have been deeply buried by terrorist networks and countries developing weapons of mass destruction.
"They have tunneled and tunneled and tunneled," he said. "How do you deal with it?"
"The Defense Department is charged with how do we defend our country. So these people ... do exactly what they are supposed to do. They screw their head into these problems and say, 'gee, there are three or four ways we can do that'. And one of them may be something that would be a deeply penetrating capability," Rumsfeld added.
And, if he does, will we find out about it sooner or later?
Regardless of how "small" or "targeted" these things are, and regardless of any justification about how they might "compare favorably" with some more conventional weapons, there is some scary symbolism surrounding letting the nuclear genie out of the bottle again. I don't think these people understand that.