AT the beginning of the Gulf war, Iraqi poison gas figured prominently in Pentagon planners' concerns. Mystery surrounded Saddam Hussein's chemical weapons arsenal: How much gas did he have, and what kinds? Could he deliver it with bombs? Shells? Scud missile warheads?
Fortunately for the United States-led coalition forces, no chemical nightmares came true. Iraqi military leaders never resorted to poison gas use. Perhaps they feared retaliation, or lacked defensive equipment. Perhaps the war just ended too soon.
Since the war's end, dogged United Nations inspection has done much to strip away the veil surrounding Iraq's weapons of mass destruction. While attention has focused on nuclear revelations, in many ways information gathered about Iraqi chemical weapons has been just as important. Among key UN findings:
* Iraq did, indeed, have a stockpile of some 46,000 chemical munitions of various types.
* Although they were never fired, Iraq had at least 30 chemical-filled warheads for Scud ballistic missiles.
* The quality of Iraqi chemical weapons is very poor. The Scud warheads might have broken up in flight; hundreds of poison munitions are now leaking and dangerous.
UN inspectors have taken the Western world's first extensive look at the Al-Muthanna State Establishment, the major chemical-weapons facility known outside Iraq as Samarra. Many of the installation's buildings were heavily damaged by allied bombing, but Western intelligence agencies still worry about Saddam Hussein's chemical weapons potential. (Western officials ponder control of former Soviet Union's nuclear arsenal, Page 5.)
"Much of the hard-to-get production equipment was removed and hidden before the bombing started," said Robert Gates, director of central intelligence, last week. "If UN sanctions are relaxed, we believe Iraq could produce modest quantities of chemical agents almost immediately, but it would take a year or more to recover the chemical-weapons capability it previously enjoyed."
Under the terms of the cease-fire agreement ending the Gulf war, chemical-arms inspection teams of a UN special commission have been visiting Iraq since the middle of last year.
In December, a UN team found metal-working machinery from a chemical-weapons bomb plant hidden at a sugar factory in Mosul. The inspection work has proved hazardous. The large Al- Muthanna facility was littered with unexploded bombs and damaged chemical drums when UN teams first entered it last fall. On one September visit a 122-mm rocket warhead that was supposedly unfilled suddenly burst, exposing a nearby Iraqi worker to a nerve agent. A Dutch UN inspector got the victim to the base hospital in time t o save his life. Still, "the incident illustrates ... that the recovery and destruction of Iraq's chemical weapons ... will be a protracted and dangerous undertaking," says a UN special commission report.
The arsenal to be destroyed is varied and sophisticated enough to be worthy of a developed industrial power. The total of 46,000 filled chemical munitions includes some 20,000 mortar shells filled with military-strength tear gas that were destroyed by coalition bombing.
The remaining 26,000 weapons include bombs, artillery shells, 122-mm rocket warheads, and ballistic missile warheads filled with mustard agent or nerve gas.
Chemicals stored in barrels at Al-Muthanna, the only place Iraq filled such munitions, include 225 tons of nerve agent and 280 tons of mustard gas. The 30 chemical-filled Scud ballistic missile warheads were found by UN inspectors in the Dujayl area, about 30 kilometers (18 miles) from where Iraq had said they were located. Sixteen of the warheads were filled with straight nerve gas; the other 14 turned out to be "binary" weapons, filled with two different chemicals intended to mix and become lethal only
Western experts were surprised to discover Iraq had binary warheads, even though Saddam Hussein had publicly hinted at such a capability. "We all thought he'd heard the US had this, and so he just threw it out there," says Lee Feinstein, assistant director of research at the Arms Control Association.
The Scud chemical warheads were very poorly made, however, and UN experts judge it likely they might not even have worked. Poor workmanship throughout the Iraqi chemical program was evident: Bulk nerve agent stored at Al-Muthanna has already undergone extensive degradation and is generally now only 10 percent of its original strength.
Many of the 122-mm rocket warheads are already leaking. "Explosive demolition was considered to be the safest means of achieving their destruction," says a UN report.
The UN hopes to begin destruction of a chemical plant at Al-Muthanna sometime early this year.