The Iraqis have used mustard gas, Sarin and VX in previous military actions. VX is particularly bad because it is a sticky persistent substance that remains poisonous for days. You don't have to breath VX to die from it. All you need to do is touch it. If our troops are sprayed with this material, they'll be trapped in their HazMat suits wearing gas masks for days. Sarin is not persistent but very poisonous. Mustard gas is just plain nasty. More people end up permanently injured by it than being killed by it. Thousands of people were crippled by mustard gas in World War I. The long term health damage caused by chemical weapons was the main reason why they were banned. If Saddam uses these weapons, we may end up nuking him which would make the situation even worse.

Gary