DHAHRAN, Saudi Arabia -- The Iraqi military, once touted as the world's fourth largest, has simply vanished into the desert sands, leaving behind only pulverized debris and a host of troubling questions.
Eleven days after the war ended, U.S. commanders are still no better prepared to answer some of the most nagging ones:
* The U.S.-led coalition claims to hold 60,000 Iraqi prisoners of war. Where are the 470,000 other Iraqi soldiers reported to have been in southern Iraq and in occupied Kuwait when the air war started Jan. 17?
* Why did Iraq's army collapse so quickly? Only hours into ground combat, its troops were surrendering in droves, including some who simply gathered in a knot, put coils of barbed wire around themselves, raised a white flag and waited for the allies to capture them.
* What happened to the much-vaunted Republican Guard? The 150,000 warriors were once compared to the U.S. Marines, but apparently fought only slightly better than their supposedly less elite comrades.
* Why didn't Iraq use chemical or biological weapons? Did it fear tit-for-tat allied retaliation? Or was it holding back, waiting to use them at an opportune time that never came?
* What happened to the notorious "Saddam Line" of Iraqi defenses? Did Iraq fool the U.S. military into overestimating it? Or did the Pentagon do so on its own, perhaps to lure Baghdad into a false sense of security, perhaps to make the U.S. public believe its task was much harder than it really was?
* And if the battle was truly so unequal, did U.S. planes and artillery really need to annihilate an Iraqi convoy that was withdrawing in panic and disarray from Kuwait City, creating the famous Highway of Horrors?
POWs say now that up to one-third of Iraq's front-line soldiers had deserted to the north by Feb. 27. That could be about 100,000. Another 60,000 or more are POWs. Iraqi officials told Iranian counterparts in January that 60,000 to 80,000 had been killed or wounded.
That totals at least 220,000, which leaves about 310,000 unaccounted for. Most are believed trapped between U.S. units arrayed north, west and south of the city of Basra, still armed but too dismembered to fight.
U.S. commanders claim that the destruction extended to the Republican Guard, 150,000 hand-picked fighters with Iraq's best weaponry. "We killed 630 tanks. . . . I don't think there's any doubt that we destroyed the Republican Guard," said the 1st Armored Division's commander, Brig. Gen. Ronald Griffith.
But the Republican Guard was still in good enough shape last week to obey Baghdad orders to crush an anti-Hussein uprising in Basra. Its soldiers even got a pay raise.
There already are questions about who is to blame for overestimating the Iraqi army.
"The press made him out to be 8 feet tall," General Griffith said, apparently forgetting the Pentagon's often-repeated assessments of Iraqi capabilities and predictions about the mines and other horrors of the "Saddam Line" of defensive obstacles the Iraqis had built across southern and western Kuwait.
Minefields that U.S. Marines anticipated would be 2,000 yards deep turned out to be only 140 yards deep. Yawning, oil-filled trenches turned out to be mere ditches 2 to 3 feet wide. The massed troops expected to have been dug in behind the defenses turned out to be mere handfuls.
The two parallel rows of 12-foot sand berms that were the heart of the Saddam Line in southeastern Kuwait were almost missed by journalists driving through them, eroded by desert winds.
Most underground bunkers, once described as formidable redoubts similar to France's famed Maginot Line, turned out to be roofed with two rows of sandbags and corrugated iron sheets, too thin to stop even mortar rounds.
A field of steel rods driven into the desert north of Iraqi lines to prevent helicopter-borne troops from landing behind them was only a half-mile wide -- an almost infantile attempt to defeat choppers that could land almost anywhere in the vast desert.
U.S. GIs who picked up Iraqi helmets as war souvenirs found that they were all fiberglass liners.
No evidence of stockpiles of chemical or biological weapons was ever found, puzzling GIs who had attacked in clumsy charcoal-lined suits.
CIA Director William H. Webster had told Congress before the war began that Iraq had stockpiled 1,000 tons of nerve and blister canisters for its artillery guns, mortars and ground-to-ground rockets.
U.S. commanders speculated that Iraq didn't have time to deliver the gas to front lines, despite earlier Pentagon claims that Baghdad had authorized commanders down to the battalion level to use chemical weapons at will.
Indeed, the only threat that the Iraqi troops were able to make good on during "the mother of battles" was the wanton devastation of Kuwait, setting more than 650 oil wells afire and spilling 2 million gallons of crude into the Persian Gulf, although even that was one-sixth the amount the Saudi military first estimated.
The prewar size and might of the Iraqi army may have been exaggerated by Saddam Hussein or by the U.S. military. According to the Department of Defense:
* Before the war, some estimates put Iraq's army at a million men including reserves. The estimate of Iraqi forces in the war zone: 530,000.
* Iraqi soldiers captured by coalition forces: 62,000+.
Iraqi deserters who allegedly fled north: 100,000.
Soldiers killed by coalition forces: Unknown. Iraq has said 60,000 to 80,000 died. Other estimates have reached as high as 100,000.
What's left of the Iraqi army's equipment? According to the Pentagon:
* 510 of 3,110 pieces of artillery.
* 470 of 2,870 armored vehicles.
* 580 of 4,280 tanks.