The images have been particularly fearsome: civilians and soldiers scrambling to don gas masks as air raid sirens blare and government broadcasts tell how to prepare for the worst.
The missile-delivered chemical attack may never come, but the potential ability of Iraq to deliver chemical weapons this way is of the highest concern to citizens and soldiers caught up in the Persian Gulf war.
And repeated Scud missile launches by Iraq against cities in Israel and Saudi Arabia have fueled the hysteria and confusion even though it is believed that none of the missiles carried chemical warheads.
Several Israeli citizens, including a 3-year-old, suffocated because they fitted their protective masks improperly during alerts after Scud missile attacks.
In the face of the attacks, military experts are debating the chemical threat posed by Saddam Hussein.
Not since World War I have U.S. troops been at such a serious risk of chemical attack, say chemical warfare specialists at Aberdeen Proving Ground in Edgewood, where U.S. production of such weapons began in 1917 and where most of the U.S. military's equipment to defend against them was developed and tested.
The 650 scientists and engineers at the proving ground's Chemical Research, Development and Engineering Center, with an annual budget of more than $200 million, continue to perfect the heavy protective suits, masks and other garb used to help soldiers survive and fight on tainted battlefields. Electronic sensors to warn of chemical attacks and an array of decontamination equipment also were products of the chemical center's research.
Though manufacture of chemical bombs stopped there in the 1940s, much of the engineering work for binary weapons -- the new class of U.S. chemical arms -- occurred there.
The United States began producing binary weapons in the late 1980s. They are safer for storage and transport, because they use two separate compounds that mix to form a lethal agent only after an artillery shell or rocket is fired.
Scientists at the proving ground, people considered world authorities on the subject, say they have been jolted by a portrayal of imminent chemical attack on live television.
In the hours after the first Scud missile attacks on Israel, journalists from across the country jammed the phones at the chemical center's public affairs office, trying to get information about the types of chemicals that might be used and their effects.
Experts are at a loss to explain why Iraq has not yet used chemical weapons, considering its propensity for using them during the eight-year Iran-Iraq war in the 1980s.
Many say it is feasible, if technically difficult, to attach chemical warheads to the Scuds, which seem to be the only way Iraq could launch a chemical attack against civilian populations in Israel and Saudi Arabia.
Iraq did use chemical bombs dropped from planes and helicopters in its war with Iran, but military commanders say Iraq's air force appears too weak to do that to any great extent in the current conflict.
Other military analysts and officers in Saudi Arabia, however, say they don't know with certainty how many of Iraq's warplanes are left. Some may have been concealed for later attacks, those analysts say.
"Whether or not they have a chemical capability for the Scuds has always been an issue," said Michael A. Parker, technical director at the proving ground's chemical center. "No one knows for sure except the Iraqis."
The Israeli reaction, assuming that every missile could carry a chemical warhead, "is certainly prudent until the evidence is to -- the contrary," Parker said.
The Iraqi military may be using the early missile attacks to hone their aim for further attacks, said Elisa D. Harris, a senior research analyst at the Brookings Institution in Washington, who specializes in chemical warfare.
That aside, she said, the threat to allied forces during a ground conflict is equally serious.
Parker and other officials at the chemical center maintain that U.S. troops are far better prepared for chemical war than were Iranian soldiers.
Repeated chemical drills by soldiers since the Persian Gulf crisis began in August have sharpened their defensive skills, Parker said. "The forces have been in there for six months now. They have had time to get used to it."
If U.S. soldiers had to fight in the protective suits for extended periods, according to a 1985 report of a presidential commission studying chemical warfare, "simple and frequent bodily needs like drinking, eating and elimination would become major preoccupations."
"Even if chemical weapons are used only against limited areas," the commission said, "if an attacker can force a defender to put on protective gear from the expectation of such use, the military effectiveness of the encumbered personnel is cut by 50 percent or more."