"According to Seymour Hersh's 1983 book, The Price of Power, Kissinger learned of Johnson's peace plans and warned the Nixon-Agnew campaign. "It is certain," Hersh wrote, "that the Nixon campaign, alerted by Kissinger to the impending success of the peace talks, was able to get a series of messages to the Thieu government making it clear that a Nixon presidency would have different views on the peace negotiations."
The chief emissary was Anna Chennault, an anti-communist Chinese leader who was working with the Nixon-Agnew campaign. Hersh quoted one former Johnson Cabinet official as stating that the U.S. intelligence "agencies had caught on that Chennault was the go-between between Nixon and his people and President [Nguyen van] Thieu in Saigon. ... The idea was to bring things to a stop in Paris and prevent any show of progress.""