WASHINGTON — THE Pentagon is taking the threat of Iraqi chemical weapons so seriously that United States troops deploying to the Persian Gulf are carrying the very latest in chemical defensive gear, according to Army officials. Besides standard gas masks, oversuits, boot covers, and gloves, US forces will have tent-like collective protection shelters. Hand-held, high-tech chemical detectors that the Army began buying just last year are being sent to Saudi Arabia.
Even an experimental device called the XM-21 that can spot a gas cloud 3 to 5 kilometers away may have been pressed into service. ``I'm told we sent all we've got to the Middle East,'' says one knowledgeable source.
That does not mean US forces would be immune to chemical attack. Iraqi leader Saddam Hussein has a formidable poison arsenal - and wearing defensive gear in Saudi Arabia's heat would be extremely debilitating.
But analysts claim Iraq would gain little militarily from the use of chemicals against a trained, prepared foe, especially in light of the likely US response of massive conventional bombing.
``Once the shock of their use wears off, chemical weapons don't produce as many casualties as people think,'' says Thomas McNaugher, foreign policy fellow at the Brookings Institution.
The standard Army chemical protection suit is a jacket-and-trouser ensemble made of two fabric layers. The outside layer is treated to repel oil and water; the inner layer is impregnated with charcoal to absorb any chemical agent that seeps through.
The rubber gas mask has a cheek-mounted charcoal filter, plus a drinking attachment and voice emitter. A hood for protection of neck and shoulders, rubber covers to wrap around boots, and rubber gloves complete the chemical outfit.
When wearing all this equipment, soldiers are said to be in Mission-Oriented Protective Posture (MOPP) 4. Troops in defensive positions in Saudi Arabia are likely to be kept in MOPP 2, says Jeff Lindblad, a spokesman for the Army Chemical Research, Development and Engineering Center. That means they will be wearing their oversuit, and carrying all other protective gear on their person. ``You can unzip the jacket,'' Mr. Lindblad says.
Each soldier is also supposed to carry a syringe full of nerve gas antidote and detection paper that changes color when exposed to chemical agent. New hand-held chemical-detection devices which work via ion spectroscopy are also being issued to the troops.
The most likely military targets for chemical attack would be airfields, according to US analysts. Airfields are large, fixed installations which if contaminated with persistent agent could be put out of action for an indefinite period of time.
Against Iran and Kurdish rebels, Iraq used chemical weapons delivered via aircraft bombs or spray tanks. Considering the growing strength of US air forces in the Arabian peninsula, such an approach would now be difficult for Saddam.
More threatening is the prospect of chemical warheads delivered by Iraq's modified Scud B surface-to-surface missiles. Saddam may not have the technology to make chemical missile warheads, but US forces are proceeding on the worst-case assumption that Iraq has such a capability. ``Anything is possible,'' says a US government expert on the Iraqi missile program, pointing out that Iraq has already demonstrated a mysterious ability to extend the range of their Scuds.
Of course, just having to put on chemical defensive gear could put US troops at a military disadvantage. In Saudi Arabia's fierce heat, even wearing just an unzipped oversuit could be as hot as sunbathing enclosed in a plastic bag.
Tests run in 1985 by Army doctors showed that even on a typical hot US summer day, far cooler than those in the Arabian peninsula, defensive gear severely limits soldier endurance. In one typical test, howitzer crews were slowed to one-half to one-quarter their normal firing rate, and could fight for only four hours at most.