Anthony Cordesman, an ABC News Terrorism consultant, says chlorine is not an efficient killer because it disperses too easily, particularly when detonated by a bomb. The shockwave alone will disperse chlorine gas too quickly to cause life-threatening damage. But, says Cordesman, chlorine and chemicals in general could be a "a major weapon in terms of publicity."
Iraq's political and military leaders say insurgents are simply trying to frighten the public by using chemical weapons in the hopes of making Baghdad's central government look weak.
Iraqis are sensitive to chemical attacks. During the Iran-Iraq war, chemical weapons were used and hundreds, if not thousands, of Iranians and Iraqis died hideous deaths.
Currently in Iraq, the trial of "Chemical Ali" continues. He was alleged to have used chemical weapons against Kurds in northern Iraq during the Anfal campaign.
Perhaps of even more concern are indications that insurgents are experimenting with the use of other chemicals and using them in conjuntion not only with bombs but also with rockets.
Chemical, bomb, and rocket-making instructions can be found on insurgent websites and throughout the online world in just about every language. And Ian Day, ABC News' Security Consultant, points out there are now online videos showing insurgents making chemical rockets. The use of chemicals, says Day, is "very amateurish for now, but they could learn how to do this better."
The top U.S. ground commander, Lt. Gen. Ray Odierno, says that chlorine canisters and other chemicals have been discovered at several sites in Iraq during raids and for now, they are studying what these new weapons will mean on the battlefield.
The big concern may eventually be the hardest to resolve. Despite the fact that their current bombs are simplistic in design, it's possible that if the insurgents keep testing, they might find a better way. For now, says Odierno, U.S. forces have to do "what we can do to try to stop them from detonating them at all."