The United Nations was fully aware that Saddam had established his chemical-weapons plants under the guise of a permitted civilian chemical-industry infrastructure. Plants inspected in the early 1990s as CW production facilities had been set up to appear as if they were producing pesticides, or in the case of a giant plant near Fallujah, chlorine, which is used to produce mustard gas.

When coalition forces entered Iraq, "huge warehouses and caches of 'commercial and agricultural' chemicals were seized and painstakingly tested by Army and Marine chemical specialists," Hanson writes. "What was surprising was how quickly the ISG refuted the findings of our ground forces and how silent they have been on the significance of these caches."

Caches of "commercial and agricultural" chemicals don't match the expectation of "stockpiles" of chemical weapons. But, in fact, that is precisely what they are. "At a very minimum," Hanson tells Insight, "they were storing the precursors to restart a chemical-warfare program very quickly."

Kay and Duelfer came to a similar conclusion, telling Congress under oath that Saddam had built new facilities and stockpiled the materials to relaunch production of chemical and biological weapons at a moment's notice. At Karbala, U.S. troops stumbled upon 55-gallon drums of pesticides at what appeared to be a very large "agricultural supply" area, Hanson says. Some of the drums were stored in a "camouflaged bunker complex" that was shown to reporters -- with unpleasant results.

"More than a dozen soldiers, a Knight-Ridder reporter, a CNN cameraman, and two Iraqi POWs came down with symptoms consistent with exposure to a nerve agent," Hanson says. "But later ISG tests resulted in a proclamation of negative, end of story, nothing to see here, etc., and the earlier findings and injuries dissolved into nonexistence. Left unexplained is the small matter of the obvious pains taken to disguise the cache of ostensibly legitimate pesticides. One wonders about the advantage an agricultural-commodities business gains by securing drums of pesticide in camouflaged bunkers 6 feet underground. The 'agricultural site' was also colocated with a military ammunition dump -- evidently nothing more than a coincidence in the eyes of the ISG."

That wasn't the only significant find by coalition troops of probable CW stockpiles, Hanson believes. Near the northern Iraqi town of Bai'ji, where Saddam had built a chemical-weapons plant known to the United States from nearly 12 years of inspections, elements of the 4th Infantry Division found 55-gallon drums containing a substance identified through mass spectrometry analysis as cyclosarin -- a nerve agent.

Nearby were surface-to-surface and surface-to-air missiles, gas masks and a mobile laboratory that could have been used to mix chemicals at the site.

"Of course, later tests by the experts revealed that these were only the ubiquitous pesticides that everybody was turning up," Hanson says. "It seems Iraqi soldiers were obsessed with keeping ammo dumps insect-free, according to the reading of the evidence now enshrined by the conventional wisdom that 'no WMD stockpiles have been discovered.'"