I truly feel that any use of a "nuclear weapon" whether it be a ICBM, tactical artillery shell, or a bunker buster is crossing the line that should not be crossed. If we start doing this, who are we to say if other nations do not start doing the same way. To top it off, what is the ethical difference between a bunker penetrator and a tactical nuke shell. One detonates under ground, the other above ground, but both are nuclear weapons. This development bothers me, because I think it is an angel hair away from opening the rest of Pandora's Box.