The revelations about the massacre of Vietnamese civilians committed by American soldiers in the village of Son My broke in November 1969, twenty months after the massacre had occurred. It swiftly became known as the My Lai massacre, because much, though not nearly all, of the killing had occurred in the settlement (within the Son My jurisdiction) marked on American maps as My Lai (4). Over the next few years, a number of book-length journalistic accounts of the massacre and subsequent attempts to bring the perpetrators to justice were published. Thereafter the rate of production slowed. For Americans, if not for the bereaved inhabitants of Son My, the massacre passed into history, and it was left to historians, therefore, to work away at the sources and assess the meaning of what had happened – for understandings of how the Vietnam War had been fought, for the training and operational practices of the modern US military, for the conduct of military justice, for concepts of American moral exceptionalism, and – not least – for those Vietnamese seeking to rebuild their lives and families out of the desolation that Americans soldiers had made of their village.

Until quite recently, not many American historians elected to undertake this task. In 1998, James S. Olson and Randy Roberts produced a short account of the massacre, combined with documentary readings, aimed at a college audience. A few years later, Michael Belknap provided a well-researched and very readable (if ultimately disheartening) history of the court-martial proceedings that followed the massacre revelations. Otherwise, the pattern seemed to be one of neglect, which both reflected and served to reinforce the peripheral status of the massacre in American “collective memory.” Was the lack of a credible introductory account of the massacre simply evidence of market indifference (the modern university student was unlikely to want to take the sort of course that such an account would support), or did the deficits of popular memory result at least in part from the unavailability of a good entry-level text? Now we can find out, for William Allison's new survey account of the massacre, its aftermath and its legacy is very good indeed.

Of particular value is Allison's careful description of what actually happened in Son My on the day of the massacre. Military investigators gathered hundreds of firsthand accounts – from perpetrators, bystanders and victims – but constructing an authoritative narrative of events in the village from this archive of partial, sometimes self-interested and often contradictory testimony represents a different order of challenge. Soldiers crossed and crisscrossed the terrain, exchanging companions as they went, occasionally setting out on their own, idling at some killing sites, moving quickly past others, as if browsing the opportunities for atrocity. Probably no one shot more people than Lieutenant William Calley, but there were many other acts of violence occurring at the same time in which he did not play a role. Allison's account expertly encompasses the whole of Son My, showing how the killing proceeded in different sites throughout the day. There may be no better way to begin teaching a course on the massacre than by requiring students to read this twenty-five-page chapter.