The CIA denied there was any cover-up. ““It’s very important to explain publicly that we are not holding back information,’’ CIA Director John Deutch told NEWSWEEK. Pentagon officials pointed out that a massive scientific inquiry has been looking into the veterans’ ailments for years now. ““Make no mistake, they are experiencing real symptoms and illnesses with real consequences,’’ says Dr. Stephen Joseph, the Pentagon’s top health official. But the science is being overwhelmed by politics in what Joseph calls a ““tidal wave’’ of conspiracy theories and cover-up charges. Veterans groups and their sympathizers in Congress are clamoring for action on the syndrome. Last September one key figure, Democratic Sen. Jay Rockefeller of West Virginia, said Joseph should resign. ““It’s time to face the music,’’ said Rockefeller. ““Way past time.''

Earlier this year Patrick Eddington, 33, and his wife, Robin, 32, quit their jobs as CIA photo analysts to crusade against what they see as a government ““stonewall.’’ Last week Patrick Eddington told NEWSWEEK that the CIA refused to accept his conclusions about Iraqi gas attacks because it had ““bureaucratic pride of ownership’’ in a different version of the events. ““Nobody in the agency wanted to hear,’’ he said. ““My evidence posed too many problems for everyone.’’ Eddington is writing a book called ““Gassed in the Gulf,’’ and to support the argument, his publisher placed on the Internet more than 200 documents previously released, and then reclassified, by the CIA–prompting the agency to declassify them again.

The CIA said there were serious flaws in the Eddingtons’ theory. The evidence they cited had already been studied by experts inside and outside the government, without convincing them that U.S. troops had been attacked with poison gas. And so far, the weight of the scientific evidence is that nerve gas does not cause the ailments reported by many veterans.

The CIA claims it did not impede the Eddingtons’ investigation. The couple became involved in 1994, when Robin Eddington worked for the then Sen. Don Riegle, a Michigan Democrat who was one of the first to investigate the mysterious illnesses. She enlisted her husband in a probe of their own. Patrick Eddington acknowledges, reluctantly, that the CIA gave him permission to conduct his own investigation and present his findings to top officials. Combing the archives, he found 59 documents demonstrating, in his view, that Saddam Hussein had used chemical weapons during the war. But the agency’s experts didn’t see it that way. Then Eddington made his case to Clinton’s independent Presidential Committee on Gulf War Veterans’ Illnesses, and most of its experts were equally unimpressed by his 59 documents. ““Our analysts have looked at literally thousands of such documents,’’ says committee spokesman Gary Caruso. ““Nothing in Eddington’s documents startled them or seemed out of the ordinary.''

The differences were largely a matter of interpretation. One document, for example, described the movements of chemical weapons from one Iraqi depot to another that was slightly closer to the front. CIA analysts assumed Saddam was dispersing his arsenal in anticipation of allied air strikes. ““Eddington said this proved his intention to use [the arms] offensively,’’ says Caruso.

Other analysts are still trying to figure out whether a Gulf War syndrome exists at all. So far, there is no statistical evidence that veterans of the gulf conflict are sicker than any others. Later this month the Naval Health Research Center in San Diego will publish a study of more than 1.2 million veterans, showing that those who served in the gulf have about the same hospitalization rate as those who did not serve there. Other studies–on mortality rates, cancer rates, reproductive health and work days lost to illness–show no significant differences between the two groups.

But when gulf veterans complain about health problems, some of them turn out to be ill for no clear reason. The government now offers them detailed clinical examinations. Of more than 22,000 who have been studied so far, about 18 percent, or some 4,000 troops, were diagnosed as having ““signs, symptoms, ill-defined conditions’’ indicating an unexplained illness. It isn’t known how many of the ailments were contracted in the gulf. Joseph says many of these symptoms ““are not very unusual in the population at large. The doctors’ offices of this country are filled with people who say, “Doc, I just don’t feel right’.''

After years of denial, the Pentagon conceded last summer that thousands of U.S. troops may have been exposed to nerve gas when Iraqi arms depots were blown up after the war. And while the fighting was underway, ultrasensitive detection equipment sounded hundreds of alarms indicating the possible presence of poison gas. Most of the alarms were false, but about 35 are still being investigated. In any case, extensive studies by military and civilian scientists have failed to show that exposure to quick-killing nerve gas can cause the chronic, low-level symptoms of Gulf War syndrome. Scientists are now looking at a variety of possible causes. They include sand flies, stress and chemical reactions between insecticides and a drug given to troops as protection against nerve gas.

As the search continues for a definitive solution, some government critics are not prepared to accept any answer that comes from the Pentagon or the CIA. ““We want to see somebody else handle the investigation, either a special select committee or an independent commission with subpoena power,’’ says Matt Puglisi, an official of the American Legion. Five years after the war, the flush of victory is gone, and only the nagging questions remain.