Opposition to United States involvement in the Vietnam War An infamous photo of General Nguyễn Ngọc Loan shooting an alleged terrorist in handcuffs during the Tet Offensive also provoked public outcry. Another element of the American opposition to the war was the perception that U.S. intervention in Vietnam, which had been argued as acceptable because of the domino theory and the threat of communism, was not legally justifiable. Some Americans believed that the communist threat was used as a scapegoat to hide imperialistic intentions, and others argued that the American intervention in South Vietnam interfered with the self-determination of the country and felt that the war in Vietnam was
US signals intelligence in the Cold War least in house arrest. A quote from "Life" magazine, generally considered friendly to Diem, suggested that a substantial number of non-communists had been arrested. This is followed by a brief note, "Yet in that same process of neutralizing opposition, Diem set the seeds for his own downfall." This followed by long redactions. Both Diem and the US Military Assistance Advisory Group (MAAG), according to the NSA history, felt the communists were going into "last gasps" in late 1959. US SIGINT support during the Vietnam War came principally from service cryptographic units, with some NSA coordination. Units still belonged to their