Mrs. Chennault was one of the most visible private citizens in Washington: a vice president of the Flying Tiger Line, a cargo line founded by Robert Prescott, a pilot who had flown with her husband during the war; a writer of novels, poetry and nonfiction books; a Voice of America broadcaster; and the center of a social whirl at her Watergate penthouse that drew in cabinet members, congressmen, diplomats, foreign dignitaries and journalists.

But there was a hidden side to Mrs. Chennault’s affairs, historians say. She was known to have been a conduit for Nationalist Chinese funds for the Republican Party, and to have been a secret go-between for American officials and Asian leaders like Chiang Kai-shek, the Nationalist Chinese generalissimo, and President Nguyen Van Thieu of South Vietnam.

And in a contretemps of international intrigue and presidential politics that generated heated debate for years, Mrs. Chennault was recorded on an F.B.I. wiretap helping to sabotage a peace initiative during the Vietnam War in order to promote Nixon’s victory over Vice President Hubert H. Humphrey in the 1968 presidential election.

Soon after President Lyndon B. Johnson announced a halt to the bombing of North Vietnam to ease the way for Paris peace talks that fall, Mrs. Chennault, a behind-the-scenes liaison for Nixon’s campaign and the Saigon government, was overheard urging South Vietnamese officials to boycott the Paris peace talks, saying they would get a better deal from a Nixon administration if they waited until after the election.