[El Blanco]

Its isn't the missiles we worried about, its what they put in the warheads. Those are the WMD.

Think about what a nuclear, chemical, or biological weapon does after the explosion. Radiation, toxins, bacteria, virus or something along those lines settle in the area, making it inhabbitable. They also get into the air and can blow around to the surrounding region.

A bunker buster pierces the ground, explodes, and thats it. Target destroyed, send in your troops. No enviormental damage (except a little jet fuel). That land can be used as soon as the fires from the underground structure are put out.