Despite its denials, Iraq probably possesses large stockpiles of nerve agents, mustard gas and anthrax, former U.N. inspectors say.
While Saddam Hussein probably does not have a nuclear bomb, the Iraqi president does have the designs, equipment and expertise to build one quickly if he can get enough weapons-grade uranium or plutonium, the former inspectors and other experts says.
Members of the U.N. teams that investigated Iraq's weapons of mass destruction from 1991 to 1998 say Saddam probably also has at least nine long-range Scud missiles, and has or easily could make chemical and biological weapons to arm those missiles.
"That's what I'd worry about -- they could reconstitute these weapons fairly soon, and they actually have stuff on hand that could be used for terrorist and military purposes," said former U.N. inspector Raymond Zilinskas, head of the Chemical and Biological Weapons Nonproliferation Program at the Monterey Institute of International Studies.
Still, many former inspectors say Iraq's arsenal is not much of a threat. They say Saddam has been deterred so far by threats of massive retaliation by the United States and other countries and apparently has been reluctant to share his weapons with terrorists.
"Possession of the weapons themselves don't, in my view, offer a proximate threat to the United States or to our friends in the region, and I'm including Israel in that," said Robert Gallucci, a former deputy director of the U.N. weapons inspection program.
President Bush says Saddam's chemical, biological and nuclear weapons programs are the main reason he must be removed from power, perhaps with military force. But administration officials have offered few details of what weapons or capabilities they believe Iraq has.
Iraq's weapons could include:
--The nerve agent VX, regarded as the most toxic of chemical weapons.
--The nerve agent sarin, a liquid or gas that causes a choking, thrashing death.
--Mustard gas, a blistering agent that can dissolve flesh on contact and severely damage the eyes and lungs.
--Anthrax, the deadly bacteria used in the mail attacks on government and the news media last year.
--Botulinum toxin, a substance produced by bacteria that causes paralysis and death.
--Aflatoxin, a poison produced by a grain-eating fungus.
Inspectors say Saddam probably has made more such weapons in the four years since the U.N. teams left Iraq.
"Any reasonable assessment of where they are now would say they probably regenerated stocks of both mustard (gas) and nerve agents," said Gallucci, now the dean of Georgetown University's School of Foreign Service.
"Botulinum toxin and anthrax -- that is not speculation, they have produced both. One would expect that over the last four years they would have produced them again."
After losing the 1991 Gulf War, Saddam agreed to scrap all of his chemical, biological and nuclear weapons programs, as well as the long-range missiles to deliver such weapons. The United Nations set up a special panel known as UNSCOM to inspect Iraqi weapons facilities and make sure all the banned weapons were destroyed.
After seven years of inspections, weapons destruction and clashes with Iraqi authorities -- who shot at inspectors and held them at gunpoint various times -- UNSCOM pulled out of Iraq in 1998 when Saddam refused to allow inspectors into presidential sites. The United States and Britain responded with four days of airstrikes aimed at damaging or destroying suspected sites of weapons of mass destruction.
In the four years since, Iraq has claimed that it ended its banned programs and destroyed all its weapons. Former inspectors and U.S. officials have accused Iraq of continuing with those programs.
"Nobody really knows what Iraq has," said former inspector Jonathan Tucker. "You really can't tell from a satellite image what's going on inside a factory."
Last month, U.N. chief weapons inspector Hans Blix said he had no real evidence Iraq actually has weapons of mass destruction although inspectors still have "many open questions" about Iraq's capability.
Satellite photos show new construction at several sites linked to Saddam's past nuclear efforts, the head of a U.N. atomic weapons inspection team said Friday.
Satellite images show also that Iraq has rebuilt several facilities that in the past were involved in Saddam's banned weapons programs. They include portions of biological and chemical weapons sites at Daura, Taji and Falluja and a uranium production facility at al-Qaim, said Iraq expert Kelly Motz of the Wisconsin Project on Nuclear Arms Control.
Former inspectors and U.S. officials say Saddam has kept his nuclear weapons teams together, which they say shows Iraq still has nuclear ambitions.
Experts disagree on how close Iraq could be to making a nuclear bomb -- estimates range from months to years -- though they agree that if Saddam could obtain stolen uranium or plutonium he could have a bomb ready relatively quickly.
"If Iraq had that material, a fair assessment would be they could fabricate a nuclear weapon, and there's no reason for us to assume we'd find out if they had," Gallucci said.
It also is unclear what means Saddam has to deliver the weapons to a target. At least nine long-range Scud missiles are unaccounted for in Iraq, and experts say Saddam may have hidden enough parts to assemble two dozen or more.
U.N. sanctions also allow Iraq to build missiles with a range of no more than 95 miles -- and some experts worry that technology could easily be converted to make longer-range missiles.
Iraq also has experimented with using small military training jets as remote-controlled drones, which could deliver biological or chemical weapons. Saddam also modified fuel tanks for supersonic MiG-21 fighters with sprayers for biological or chemical weapons.
Chemical and biological weapons are more of a threat to civilians than to U.S. or coalition soldiers, who have vaccines, protective gear and training to protect themselves.