
WMD is shorthand. 687 addresses the 150 km limit.
US media, and politicians who want their sound-bite in the US media, these days can't take the time to say that missiles having range greater than 150 km are proscribed to Iraq, just as biological, chemical and nuclear weapons and production facilities are proscribed. They all get lumped under "WMD". It's just unfortunate short-hand for the weapons and weapons-systems that the UN has said Iraq is forbidden to have.
[link|http://www.un.int/usa/02_068.htm|Here]:
[link|http://www.un.org/Docs/scres/1991/687e.pdf|UN Security Council resolution 687] of April 3, 1991 will remain in force. Not only does the resolution require Iraq to destroy its nuclear, chemical and biological weapons programs, and limit the range of Iraq's ballistic missiles to 150 km. The resolution also prohibits the sale or supply to Iraq of all arms and related materials. This includes dual-use products and technologies related to military purposes as well as training and technical support. There will be no easing of restrictions on Iraq's rearmament.
Cheers,
Scott.