The United States had never lost a war--that is, until 1975, when it was forced to flee Saigon in humiliation after losing to what Lyndon Johnson called a "raggedy-ass little fourth-rate country." The legacy of this first defeat has haunted every president since, especially on the decision of whether to put "boots on the ground" and commit troops to war. In Haunting Legacy, the father-daughter journalist team of Marvin Kalb and Deborah...