What’s wrong with the B61-11?
"The B61-11 can penetrate and detonate below the earth's surface, creating a massive shock wave capable of destroying underground targets. In tests the bomb penetrates only 20 feet into dry earth, even when dropped from altitudes above 40,000 feet. But even this shallow penetration before detonation allows a much higher proportion of the explosion to transferred into ground shock relative to a surface burst. It is not able to counter targets deeply buried under granite rock. Moreover, it has a high yield, in the hundreds of kilotons. If used in North Korea, the radioactive fallout could drift over nearby countries such as Japan.
B61-11 Earth-Penetrating Weapon
(that, and the whole "glow in the dark", precedence and escallation thing...)
[I'll throw in two "/sarc" tags - one for you and one for me]
:-)