WASHINGTON -- On a September afternoon in 1970, Air Force Lt. Tom Stump flew low over Laos in his A-1 attack plane, supporting a U.S. ground operation against a North Vietnamese stronghold.
Stump unloaded bomblets on the enemy troops while other U.S. planes dropped canisters of gas. Crackling over his radio came the sounds of American troops choking and coughing.
"Those guys got a pretty good dose of the stuff," he recalled. "[The planes] went right in over our guys."
That incident is the focus of a report that the gas was sarin -- the substance that killed 12 people on a Tokyo subway in 1995 -- and that it was used against a group of U.S. defectors and that it wounded American troops positioned near the enemy.
The Pentagon is investigating the claim, and the Vietnam Veterans of America has called for a congressional investigation. The Senate Veterans Affairs Committee will determine whether to hold hearings, a spokesman said.
But classified documents and interviews with some participants in the operation have raised questions about the accuracy of the story, reported on CNN and in Time magazine last week.
The chairman of the Joint Chiefs of Staff at the time, who CNN said had confirmed the story, now flatly denies he did so.
A former Green Beret captain who was mentioned in the report says he doesn't believe sarin was used.
And a former Green Beret lieutenant who was quoted as saying sarin was part of their arsenal now says it was the show's producer who told him nerve gas was used.
A previously top-secret report of the 1970 incident, conducted immediately afterward and just released by the Pentagon, makes no mention of sarin.
Pentagon weapons experts say no lethal gas was used in Vietnam; U.S. policy forbade troops to initiate the use of nerve gas.
Rather, it was tear gas that was used that day, the Pentagon and pilots who flew the missions say. If it had been nerve gas, one general said, at least some of the U.S. soldiers would have been killed.
CNN is sticking by its story. Though some of its named sources have now distanced themselves from it, the report is also based on unnamed Special Forces, Marine and Air Force veterans, said April Oliver, the show's producer.
"They are very, very scared of [being charged with] war crimes," she said, noting that the story followed an eight-month Time/CNN investigation. "This big Pentagon inquiry, we welcome that."
Operation Tailwind was a four-day operation in Laos that began with Green Beret troops supported by Montagnards, a tribe allied with U.S. forces against the North Vietnamese.
The targeted village, CNN and Time reported, included a group of U.S. soldiers who had defected to the enemy and who might, it was feared, leak military secrets.
Softened up with sarin
One night, CNN and Time reported, sarin gas was dropped to "prepare the village for the attack."
After the firefight the next day, U.S. forces moved to a landing zone, where they were to be picked up by helicopters.
All 16 of the Green Berets had been wounded. There were 144 enemy killed, with 288 more killed by air attacks.
The CNN report, citing "military officials," said Tailwind held "two of the military's top secrets": the use of sarin and the targeting of American defectors. In addition, the report said, the nerve gas not only killed Vietnamese enemy troops but also injured some U.S. troops nearby.
CNN also said retired Adm. Thomas Moorer, chairman of the Joint Chiefs of Staff at the time, "confirmed that nerve gas was used in Tailwind."
But Moorer told the Associated Press afterward: "Whether they had sarin, you can't prove it by me either way. There were rumors that this gas had been used."
Oliver said Moorer confirmed both the use of sarin and the targeting of American defectors.
"I found Admiral Moorer to be a distinguished, thoughtful person," Oliver said. "I'm sure he's under a great deal of pressure now by his former colleagues."
Also interviewed for the story was former Capt. Eugene McCarley, who was commanding Green Beret troops.
"They didn't quote me much; I wasn't very sympathetic to what they were doing," McCarley said. "It's 90 percent lies. I'm wondering if I was on a different Operation Tailwind than the one CNN is talking about."
Oliver said McCarley told her that "very possibly" a lethal nerve gas was used.
"I said, 'Well, it's possible,' " McCarley said. "But I continued: It was never used by any of my forces, and it was never used in
Another Green Beret soldier who took part in Tailwind, Lt. Robert Van Buskirk, talks on the program and in the related Time article about nerve gas and of seeing two Caucasians at the camp.
The report said he saw the two of them run into a hole and that he threw in a grenade, which likely killed them.
In an interview, Van Buskirk says he recalls seeing Caucasians but said he had repressed the memory for years. Oliver's questioning, he said, helped revive those memories. "I let it go, CNN brought it back," he said.
McCarley said there were no reports at the time of Caucasians or non-Vietnamese at the camp.
It was CNN, Van Buskirk said, that told him about the nerve gas after he told them he had been choking and vomiting as he ran to the helicopters. He had always assumed it was tear gas.
"What they said was: 'The symptoms you're describing are the symptoms from nerve gas, not tear gas.' They said, 'What have you got to say about that?' "
Pilots who took part in the mission said they were told they would carry tear gas.
"It wasn't nerve gas," said Arthur W. Bishop, recalling the briefing he was given before taking off. "It was CBU-30, a tear gas."
When they dropped the gas, some fell onto U.S. troops, they learned from their radios.
They were told the troops "were choking and spitting because some of the gas got to them," recalled another pilot, Donald H. Feld. When Feld spoke with Oliver, "she insisted the Air Force lied to us. I told her that's foolish."
Stump said he talked with CNN's military analyst, retired Air Force Maj. Gen. Perry M. Smith, who thought the report was faulty and tried to have it pulled.
Yesterday, Smith said: "I can't comment, but I am having serious discussions with senior officials at CNN about the report."
Troops without gas masks
While the troops were issued gas masks, McCarley said, "at least a third of us didn't have gas masks."
Mike Hagen, a platoon sergeant in the operation, is convinced sarin was used. Asked why, he said: "Because I have no feelings from the knees down."
He says the Veterans Affairs Department said he is 100 percent disabled, though the agency deemed it non-service connected. But he said one VA doctor told him two years ago that he was suffering from nerve gas damage.
The day of the incident, Hagen said, he was enveloped in "a light fog" of gas as he headed for the helicopters. Lacking a gas mask, he was overcome by coughing and vomiting.
"I knew after the first breath it wasn't tear gas," Hagen said.
Pentagon officials knowledgeable about chemical weapons said if the gas had been sarin, there would have been at least some U.S. deaths during Operation Tailwind, even at low levels.
"They would not have gotten to that helicopter if that had been nerve gas," said retired Brig. Gen. Walter L. Busbee, who spent 32 years working with chemical weapons. "If you're exposed to nerve agent, you're going to die."
Busbee said the troops could have had a severe reaction to tear gas because of the intense heat and physical exertions of combat. Busbee said he knew of no evidence that nerve gas was ever used in Vietnam or anywhere else.
The Army's "Medical Aspects of Biological and Chemical Warfare," published last year, tells of a 52-year-old worker at Edgewood Arsenal in Maryland who was exposed to sarin when he was cleaning a contaminated area.
Although he was wearing full protective gear, there was a crack in his face mask. He was treated over two days with several doses of atropine, along with other medications, and survived.
Pub Date: 6/14/98