Before the Storm: Barry Goldwater and the Unmaking of the American Consensus by Rick Perlstein:
Vietnam may have been on these Democrats’ minds. Through September and early October, a flurry of cables between Washington and Saigon wrestled with a contradiction at the heart of the Pax Americana. American power wanted to be innocent. But once it became clear that South Vietnamese president Ngo Dinh Diem would not be cowed into moving toward American-style democracy by threats of losing $1 million a day in U.S. subsidies, arrangements were made with a cabal of Vietnamese generals for a “totally secure and fully deniable” coup—to advance the cause of democracy, of course. Usually the CIA carried out such orders at a remove from the presidential gaze; this coup, however, was directed from the White House. On November 1, a group of South Vietnamese generals secured Diem’s surrender by promising him safe passage out of the country. Then they shot him in the back. Kennedy, incredulous, almost convinced himself to believe the generals’ story that Diem had killed himself. National Security Adviser McGeorge Bundy brought him back to earth by reminding him of the photographs of the corpse with his hands tied behind his back—“not,” he quipped, “the preferred way to commit suicide.” It haunted the President’s conscience, what had happened there, what he had not been able to control. Soon a New York Times investigation revealed American involvement in the plot. Now it was a political problem.