Hentoff agitated against the Vietnam War and against the United States' participation. Although he said he was a "hardcore anti-communist" since the age of 15, he had "no illusions about the corrupt, undemocratic government of South Vietnam." After the war's end, Hentoff, Joan Baez, and Ginetta Sagan of Amnesty International repeatedly protested what he called "the horrifying abuses of human rights [committed] by the Vietnamese Communist regime."