Vietnam: a history, by Stanley Karnow

This is a substantial (750 page) deep dive into the Vietnam War with a heavy focus on the politics surrounding most of the major U.S. decisions about the war along with the various factions within South Vietnam that made the South particularly difficult to partner with. One of its strengths is how the author sets up the story by delving into the history of French colonialism leading to Vietnamese nationalism and later embrace of communism by many. Another strength of the book is the author's inclusion of his personal experiences as a reporter in Vietnam, allowing him to share his front-row perspective with readers. This edition was published in 1983, and some of the commentary reflects the situation in Vietnam in the early 1980s. There is a 2nd edition available from 1997, and I would recommend going with the later edition.