Staff Sgt. Edgar Rodriguez barks out orders, and dozens of infantrymen hastily pull on gas masks attached to olive-green hoods.
"You will be asked to hold your breath, break the seal, and then clear the mask," Sergeant Rodriguez instructs. "If you get a whiff of CS [tear gas] when you do that it could be nerve gas in a combat situation understood?"
"Hoo-ah!" reply the troops as they march single file toward the "chamber" a cement-floored cabin filled with tear gas.
Here in the sprawling backwoods of Fort Stewart, Georgia, the Army's 3rd Infantry Division is preparing for a possible war against Iraq including what the Pentagon considers a very real risk of Iraqi chemical or te weapons attacks. For the division's heavy infantry troops, some 2,000 of whom are deploying to Kuwait in coming weeks, war-fighting drills have taken on a complex new dimension that could spell the difference between fighting through deadly agents and being stopped in their tracks.
From narrowed vision, heat exhaustion, and mental stress for troops, to the massive logistics of decontamination, to the potential for panic among civilians, US commanders admit that lethal toxins would seriously impact the prosecution of a war.
"Does it [better US protection] mean that this is still not going to be a horrific event, that we're going to have to fight our way through?" asks Gen. Richard Myers, chairman of the Joint Chiefs of Staff. "Is it going to slow us down? Probably. Will it cause us maybe to change our plans in a localized area? It could possibly."
Despite advances in US military protective gear, sensors, and decontamination equipment since the 1991 Gulf War, senior defense and military officials say the threat of Saddam Hussein's weapons of mass destruction (WMD) programs has also grown: The Iraqi regime is developing more potent chemical and biological agents, they say, as well as pilotless aircraft, sprayers, artillery shells, and longer-range missiles with which to deliver them.
As a result, US commanders say they are planning for a worst-case scenario, in which a WMD attack would, at minimum, slow ground troops, and could paralyze an entire base or contingent.
At Fort Stewart, troops trained by Nuclear-Biological-Chemical (NBC) experts such as Rodriguez must pass tests aimed at ensuring they can protect themselves and carry out their missions amid lethal agents. Training can be an ordeal. Minutes after Rodriguez orders troops into the gas-filled chamber, the door bursts open and the young men dash out, whooping and spitting. "Wooooooh! It's strong!" yells Pfc. Anthony Young, his eyes watering and nose running.
In fact, the gas masks worked. The soldiers found out just how effective the masks were by taking them off part of a dare to see how long they could stand the tear gas. "It's a confidence booster," says Secont Lieutenant William Muraski, a battalion-level chemical weapons expert.
US forces in Iraq or nearby are most likely to face two types of WMD threats from Mr. Hussein's regime, with some weapons deployable within 45 minutes of an order to use them, according to military officials and Western intelligence estimates.
Biological weapons, which take days or weeks to act, would target concentrations of troops in fixed positions such as bases and ports, officials say. Iraq's known biological agents include anthrax, botulism toxin, and possibly smallpox. US sensors can detect biological agents about 15 to 45 minutes after exposure, soon enough to give doctors time to treat troops. In addition, the Pentagon resumed anthrax vaccinations in September and is considering a plan to begin smallpox inoculations next month for troops most likely to be exposed.
In contrast, chemical weapons, which can kill within minutes, would likely be used in an effort to stop advancing US troops. Iraq's stockpiles include chemicals such as the potent nerve gasses VX, sarin, and cyclosarin, as well as blister agents such as mustard gas. US forces have an armored scout vehicle that can detect 18 chemical agents at once from a distance of three miles; working in seconds, it gives ample warning for troops to don protective gear. Troops also carry an M-22 Acada alarm system that detects chemicals at a 300-yard perimeter, and smaller portable detection kits.
In Fort Stewart's mechanized infantry, soldiers focus on responding to chemical strikes, largely because of tactical implications. Once a chemical attack is discovered, troops immediately go to the highest stage of protection, known as MOPP (Mission Oriented Protective Posture) 4, putting on masks, gloves, overboots, and suits filled with activated charcoal. Tanks and other armored vehicles such as Bradleys are sealed up with hatches closed, forcing drivers to use periscopes. Night vision goggles can be worn over the gear.
The protections, while effective for 24 hours at a time, are cumbersome, stressful, and slow operations, soldiers and commanders say. "It's almost like putting on blinders," says Maj. Frank McLary, an operations officer. "You really have to rely on your wing man [in an armored vehicle formation] to tell you what is happening when you are buttoned up and wearing a ... mask."
Masks contain built-in microphones, but they muffle voices. The newest chemical suits, while longer-lasting and lighter than the older battledress overgarments, are still heavy (5.6 pounds), hot, and uncomfortable. "The first time out, you'll have heat casualties if you're fighting in summer," says Major McLary.
While wearing full MOPP gear in a contaminated area, basic tasks grow complex. Manuals list 17 steps for drinking water through fitted straws. Using the latrine takes 23 steps.
After exposure, decontamination procedures keep troops and vehicles out of the battle for at least several hours, experts say.
To prevent such attacks, US commanders say they would attempt to strike Iraqi WMD capabilities early in a conflict. Failing that, they warn that any Iraqi officers following orders to deploy chemical or biological weapons will face prosecution.
Soldiers such as Rodriguez are issuing a warning of their own. "Our goal is to continue the mission," he says. "If they expect us to stop, they're wrong."