Have six Iraqi pilots defected with their helicopters into Saudi Arabia this week, or haven't they?

One day after anonymous officials in Saudi Arabia leaked a report that the pilots had indeed switched sides, and after Pentagon spokesmen had confirmed it, the following developments took place yesterday:

Prince Sultan bin Abdul Aziz, the Saudi defense minister, denounced the story and said it had been "made up by CNN and foreign news agencies."

Pentagon sources said the defections were reported yesterday as fact to senior U.S. officials in briefings prepared by military intelligence officers who added details consistent with the press accounts.

Pete Williams, the top Pentagon spokesman who had confirmed the report late on Monday, said at a noon briefing yesterday it had come from Saudi officials but admitted in embarrassment that "I don't have confirmation that either this is true or it is untrue." Hours later, he called The Washington Post to say:

We have no helicopters. The Saudis have no helicopters. We have no evidence to indicate there were any helicopters."

American reporters returning from a field trip to northeastern Saudi Arabia, near the Ra's al Khafji base where the alleged Iraqi defectors landed their craft, said something had caused some excitement in the area. The reporters said they had been awakened around midnight Monday, told the base had gone on alert, warned of "incoming Iraqi aircraft" and then informed by a U.S. Marine officer that the aircraft were helicopters flown by pilots who sought to defect.

Only the Iraqi version of events -- that there were no helicopters, no pilots, no defections -- remained unchanged.

"Clausewitz spoke of the fog of war," said University of Chicago defense analyst John Mearscheimer. "This is the fog of the phony war."

Remarkably, more than 18 hours after an incident that either did or did not take place, the Defense Department was unable or unwilling to give a definitive account of what happened. As President Bush nears a decision on whether to go to war, the episode served if nothing else as a cautionary reminder of the elusiveness of truth in a combat zone.

The confusion also cast doubt on claims of a smoothly functioning liaison between American and Saudi forces allied against Iraq. Both U.S. and Saudi officials have described the relations between their militaries as cooperative and well-integrated.

Williams, who offered little else of substance yesterday, twice said the U.S. government had received its information about the Iraqi helicopters from the Saudis, and twice declined to accept Saudi denials yesterday as definitive.

"There are lots of little leads to chase down, and until they have all been chased down, I think prudence would dictate that we not try to take any further stabs at this. . . . We're saying, 'Hold the phone, we're going to go back and completely chase this down, and once we have an answer, we will get {back} to you,' " Williams said at his noon briefing. In his subsequent phone call to The Washington Post, he declined to say what steps he had taken to substantiate or disprove the report.

News of the purported defections first broke in Dhahran, Saudi Arabia, on Monday, when an unidentified source told the Associated Press, the Cable News Network and other news organizations that four Iraqi helicopters had been flown by defectors from Kuwait into Saudi Arabia. Additional details made available within hours increased the number of helicopters to six and said that two of them had been forced to land in the Saudi desert when they ran out of fuel.

Lt. Col. Mike Gallagher in Dhahran, and then Williams and Air Force Lt. Col. Rick Oborn in Washington, all Pentagon spokesmen, confirmed the reports Monday and said four of the helicopters had been escorted by F-15 fighters to the al Khafji base, about 11 miles from the border with Kuwait.

U.S. intelligence summaries prepared for senior military officials yesterday went so far as to specifically identify the craft flown by defectors as Soviet-made Mi-8 Hip transport helicopters. Other sources described written intelligence reports of unusual radio traffic between Iraqi aircraft and Saudi officers.

Hours before Prince Sultan described the whole episode as "fabricated and devoid of truth," a Saudi government source continued to describe it in detail to the Mideast Mirror's correspondent in Riyadh and asserted that "a high-level Iraqi official" was among the defectors aboard the helicopters.

Eason Jordan, CNN's vice president for international news gathering, said the network received its information "from an extremely reliable source" and confirmed it with Pentagon officials. "We don't fabricate news," he said.

U.S. officials, too, said they were amazed and confused by the Saudi government's denials yesterday that there had been any defections by Iraqi pilots.

"What exactly in hell is going on is an answer we do not have yet," said a senior administration official, who spoke on condition of anonymity.

"There's more to it than just the Saudis saying they landed," the official said. "There were people who saw helos and all that other stuff."

The officials would not say whether the witnesses were Saudi or American. Some American officers are known to have been stationed as liaison at the al Khafji base.

Sources with access to U.S. intelligence said they did not know the truth of the defection report and offered conflicting speculation about the public turnabout by the Saudis.

The Soviet Hip helicopter, one source said, looks similar in profile to the smaller French-made Puma, which is part of the Saudi arsenal. "It could have been a case of mistaken identity, augmented by the standard process of embellishment," the source said.

Alternatively, the source added, the initial intelligence reports could have been true and "it could be for some reason the Saudis don't want anybody to know they have those helicopters. But it's a great propaganda coup to have them, so I can't think of a motive to deny it."

Staff writers Caryle Murphy in Riyadh, Guy Gugliotta in northeastern Saudi Arabia and Molly Moore in Washington contributed to this report.