Johnson learned of the Nixon-Chennault effort because the NSA was intercepting communications in Vietnam. In response, Johnson ordered NSA surveillance of Chennault and wire-tapped the South Vietnamese embassy and members of the Nixon campaign. He did not leak the information to the public because he did not want to "shock America" with the revelation, nor reveal that the NSA was intercepting communications in Vietnam. Johnson did make information available to Humphrey, but at this point Humphrey thought he was going to win the election, so he did not reveal the information to the public. Humphrey later regretted this as a mistake. The South Vietnamese government withdrew from peace negotiations, and Nixon publicly offered to go to Saigon to help the negotiations. A promising "peace bump" ended up in "shambles" for the Democratic Party.