<<Since WMD is an English acronym, we can limit our examination to those countries which use English as their foremost language, which includes the United States, Great Britain, Canada, Australia, and New Zealand (for the major ones).>>
Oh, boy. Here we go again. AndrewR once again breathes fire. Oh great one, oh dragon, oh leader mostly high, please forgive me for I am but a human being adrift on the sea of life. Weapons of mass destruction are limited to U.S. military doctrine because AndrewR says so...
But hark, multinational agreements regulating the proliferation of weapons of mass destruction do more than include simple nuclear, biological, and chemical weapons. Ever hear of the Wassenaar Arrangement? Australia, UK, and the USA all list delivery vehicles along with the NBC's as weapons of mass destruction, which happens to include missiles.
During the Desert Storm operation the U.S. captured documents pointing to Iraqi weapons programs that detailed production of nerve gas, mustard gas, sarin, and anthrax weapons. The U.S. captured a few different stockpiles of weapons which included artillery shells, hand grenades, and missile warheads customized to launch chemical or biological weapons.
Weapons that deal wide-effect damage have been a concern of civilian peacemakers since before WWI. The Russians have wanted fuel-air explosives and cluster bombs regulated by treaty for more than a decade now, something the U.S. is against. Princess Diana, I'm sure you realize whom she was, talked on television about her concerns that landmines need to be regulated by international treaty as a weapon of mass destruction.
<<Are your pilots still safe at 12,000 feet from all missiles?>>
And yes, aircraft are generally safe from SAM defenses above 12000 feet when current operational procedures account for the defenses.