The U.S. government long has denied the link between Agent Orange and medical maladies of the Vietnam veterans doused with the herbicide.

Newly declassified reports show the federal government knew more than it was willing to admit about Agent Orange three decades ago, yet it continued haphazard use of the dioxin-laden chemical. The picture is of a cavalier U.S. war effort bumbling along with Agent Orange, discovering pitfalls along the way and covering them up with a propaganda campaign.

We have examined military and State Department memos that were traded on the issue of Agent Orange in the 1960s. They show that whatever the government knew about the dangers of Agent Orange, it used the defoliant anyway, in the face of questions about its safety and efficacy.

The documents suggest a government policy of making up policy as it went along and covering up the blunders.

Even from the get-go, there was more concern about rubber plantations than about the soldiers and civilians. The U.S. operations respected a secret, five-mile buffer zone around Vietnamese rubber plantations, for reasons "we must accept," according to a June 1968 memo from the U.S. Embassy in Saigon. The same classified memo refused that courtesy to populated areas.

The plantation owners had more clout than poor villagers, but even the plantations suffered because of goofs in the spraying program. A November 1967 memo to the U.S. ambassador in Saigon from his assistant noted that unintended drift of Agent Orange "was responsible in early 1967 for significant damage to the rubber plantations."

Other memos fret about this problem of drift, implying that Agent Orange was spread over even more than the 6 million acres targeted.

Our associate Dan Njegomir examined the old documents and talked to advocates who have tried for years to get the government to take responsibility for the fallout from Agent Orange. Ron Rossani, a disabled Vietnam vet who has studied Agent Orange for years, said the documents reveal "incompetence at the highest level."

As public concern grew in Vietnam and at home, the U.S. government seemed most interested in orchestrating a media blitz. One proposal that was almost adopted was an outright lie.

In late 1967 and early 1968, a series of memos proposed that the government publicly declare that Agent Orange would be banned in certain heavily populated areas. "In fact, this area would be so defined as to cover areas where there is very little use of defoliants any longer in any case," according to a secret Army memo from November 1967. "Appearing to restrict the use of defoliants," the memo continued, would have the added benefit of good psychological warfare because it would suggest "that large areas were sufficiently pacified by now."

The plan was dropped because the Army was afraid the Viet Cong would congregate in the areas touted as Agent Orange-free.

A Pentagon spokesman insisted the Agent Orange program was undertaken without an eye to public relations. "It had a military purpose and a military application only," he said.