Who do you drop a nuclear bunker buster on?

http://www.nationalreview.com/kerry/...0406020904.asp
Gen. Richard Myers, in a May 2003 briefing, explained that a nuclear
bunker buster could minimize the threat from biological or chemical
weapons at an enemy site.

By the time the nuclear bunker buster is fielded, both Iran and North
Korea will have nuclear armed missiles capable of at least striking
their neighbors, so who exactly would you use the RNEP on?

You're not going to find all of their launch locations before you strike
and afterwards they have nothing to lose by launching.

-HJC