Overview
This is the rare item in the conspiracy canon that migrated into the history books, and it did so slowly, over roughly forty years, as the relevant archives opened one after another.
The 1968 presidential election was close. Hubert Humphrey, carrying the weight of Johnson's war, had been trailing Nixon badly and was closing fast through October. The single event most likely to finish that comeback was a breakthrough in Paris: if Johnson could get North and South Vietnam to the table before the vote, the peace candidate would effectively be the sitting administration, and Humphrey would inherit it.
On 31 October, Johnson announced a complete halt to the bombing of North Vietnam and said talks would begin. Within days it collapsed. Thieu's government in Saigon announced it would not attend.
Anna Chennault
The channel ran through a woman with unusual standing in both capitals. Anna Chennault was Chinese-born, a prominent Republican fundraiser, and the widow of Major General Claire Chennault, who had commanded the Flying Tigers in China during the Second World War. That name opened doors in Asia that no ordinary campaign operative could have opened.
From 1967 she was in contact with the Nixon campaign and with Bui Diem, South Vietnam's ambassador in Washington. The message she carried to Saigon was simple and did not need to be elaborate: do not go to Paris, hold on, you will get better terms from a Nixon administration than from this one.
On 29 October 1968, days before the vote, Thieu refused to take part. Nixon won on 5 November by a margin of roughly half a million votes out of some seventy-three million cast.
What Johnson Knew
Johnson knew almost immediately, and by extraordinary means. The FBI was wiretapping the South Vietnamese embassy and had Chennault under surveillance; the National Security Agency was reading Saigon's diplomatic cable traffic. The intercepts showed the ambassador reporting contacts and encouragement from the Nixon side.
Johnson's private reaction, preserved on his own White House recordings, was blunt: he described what he was seeing as treason. He telephoned Republican senators about it. He confronted Nixon, who denied everything.
And then he did nothing publicly. The reasoning has been argued over ever since — that revealing it would have meant admitting to wiretapping an allied embassy, that the intelligence was too sensitive to expose, that he could not prove Nixon's personal direction, that the damage to the presidency and to the talks themselves would be worse than the silence. Humphrey, told at least part of it, also declined to use it, and lost.
The Notes
For decades the missing element was Nixon's own hand. Chennault later said she had acted on instructions. Nixon denied it to the end. The intercepts showed the Saigon end of the conversation, not the Washington end.
That gap narrowed when the Nixon Library's holdings opened further and researchers reached the handwritten notes of H. R. Haldeman, Nixon's chief of staff, from the campaign period. In them Nixon is recorded directing that a monkey wrench be thrown into the peace initiative, and instructing that Chennault be kept working on the South Vietnamese — with the added instruction that nothing be put in writing that could come back on the campaign. The journalist John A. Farrell brought the notes to wide attention, and they became central to his Nixon biography.
With that, the affair moved out of the category of allegation. The academic argument that remains is about consequence rather than occurrence: whether Thieu needed persuading at all, given his own strong reasons to prefer a Republican administration and to distrust the terms on offer; and whether the Paris talks, which dragged on for years afterwards, would have produced anything before the election even if Saigon had attended.
What It Established
The war continued for more than four years after Thieu stayed away from the table. The eventual settlement in January 1973 was not obviously better for South Vietnam than what had been available in 1968, which is the fact that gives the episode its long shadow.
It also left a specific residue in American politics. The Logan Act, the 1799 statute forbidding private citizens from negotiating with foreign governments in disputes with the United States, is almost never invoked; the Chennault affair is the case most often reached for whenever the question arises again, as it did during the transition of 2016. And Johnson's decision to hold a file he could not use — the intelligence that could not be revealed without revealing how it was obtained — remains one of the more studied problems in the relationship between surveillance and democratic accountability.