Until the My Lai revelations became front-page news, atrocity stories were routinely disregarded by American journalists or excised by stateside editors. The fate of civilians in rural South Vietnam did not merit much examination; even the articles that did mention the killing of noncombatants generally did so merely in passing, without any indication that the acts described might be war crimes. Vietnamese revolutionary sources, for their part, detailed hundreds of massacres and large-scale operations that resulted in thousands of civilian deaths, but those reports were dismissed out of hand as communist propaganda.
And then, in a stunning reversal, almost immediately after the exposure of the My Lai massacre, war crime allegations became old hat — so commonplace as to be barely worth mentioning or looking into. In leaflets, pamphlets, small-press books, and “underground” newspapers, the growing American antiwar movement repeatedly pointed out that U.S. troops were committing atrocities on a regular basis. But what had been previously brushed aside as propaganda and leftist kookery suddenly started to be disregarded as yawn-worthy common knowledge, with little but the My Lai massacre in between.— Nick Turse, Kill Anything That Moves: The Real American War in Vietnam (New York: Metropolitan Books, 2013), 5-6.