Some experts now believe the weapons of mass destruction have not been found because the United States may have fallen prey to a deception operation run by Saddam Hussein's intelligence service.

No definitive proof of such a deception operation has been made public. But Todd Masse, an expert on intelligence matters at the U.S. Congressional Research Service, says if the weapons did not exist, Saddam Hussein would have wanted the West to think he had them.

"Hussein was obviously running a massive denial and deception campaign," he said. "If he did not have weapons of mass destruction, then it was in his interest to have the United States think he did for reasons of regional prominence and otherwise.

"I wouldn't put it past that there were, you know, planned sort of agents who said, 'yes, I'm going to put you in touch with the Americans and the Brits or UNSCOM, the U.N. Special Commission on Iraq, and I want you to feed them disinformation,' continued Mr. Masse. "I mean, that's the intelligence business."

Much of the intelligence in the prewar period especially that provided to the Defense Department came from Iraqi exiles, such as those from the Iraqi National Congress. Martin Rudner, director of the Canadian Institute for Intelligence and Security Studies at Carleton University, says Iraqi defectors may have given U.S. officials bogus information.

"My impression now as we're sitting is that on the defector side there may in fact have been a deception operation run by the Iraqis," explained Mr. Rudner. "And this is not the first time in history that defectors were in fact double agents and were out there as part of a deception operation."

Intelligence experts say U.S. agencies had technical intelligence capabilities in abundance in Iraq. But, as Mr. Rudner points out, human intelligence was sorely lacking. "So in the end I think we had an extremely hard nut to crack with human intelligence," added Mr. Rudner. "And it doesn't surprise me that with hard nuts to crack you end up with bits and pieces of splinter and shell in your throat."

Mr. Rudner says the United States also relied heavily on human sources from British intelligence. But, he adds, even the British found it tough going. He relates the story of what happened to a British intelligence chief in Iraq some years back.

"One day their intelligence officer in place in the embassy, who of course had not been declared to the Iraqis, was picked up by a car, by some thugs, driven off to a warehouse. They open up the door, then show him hanging from meathooks on the rafter every one of his Iraqi contacts. Then they turn him around, put him back into the car, drive him to Baghdad airport, put him onto an airplane back to Britain," he reminded.

Experts say not only may the intelligence collection have been faulty, but the intelligence analysis may have been spotty as well. Mr. Masse says intelligence analysis is not an exact science, and leaves wide latitude for interpretation by intelligence consumers, the policymakers. "As you know, intelligence does not form policy," he said. "Intelligence merely informs policymakers.

"Ultimately, it's the policymaker who's making the decision, making the policy," added Mr. Masse. "And they can choose to accept or reject what comes out of a National Intelligence Estimate, like the one done in October 2002 on Iraq. They can choose to look at particular elements of it and ignore other elements, or overemphasize one element or underemphasize another. So generally what I'm saying is that there's room, there's just plenty of room, for interpretation."