The Making of a Quagmire is an absolutely heartbreaking look, a clear-eyed examination of the failures of the Vietnam War that came out just a little too late to make a difference. Halberstam drew on his experience as a reporter to chart in detail three related problems.
The first was the government of Ngo Dinh Diem: isolated, corrupt, paranoid, Diem and his brother and sister-in-law the Nhus were the rotting head of South Vietnamese politics. Everything was cast through the lens of personal loyalty and palace intrigue. At one point, there were 13 separate and warring secret police factions. Competent men who told the truth were punished, corrupt toadies rewarded. Even as American aid and advice flowed in, it was absorbed by the infinite avarice of the South Vietnamese ruling class, rather than the peasants who were the center of gravity of the war.
The second side was the War in the Delta, and the related propaganda war on the American home front. ARVN units lacked the leadership to pursue and destroy Viet Cong forces, as commanders who lost troops were sacked. The Strategic Hamlet program was a twisted joke of forced relocation against a profoundly place-based culture. Meanwhile, General Harkins at MACV and various figures in the State department were feeding back the same optimistic and fundamentally false stats. Halberstam and the other reporters were ordered to get on the team, or get out.
The final bit is the Buddhist Crisis and the coup that depose Diem and the Nhus in 1963. Through an escalating series of missteps, the Diem government forced a showdown with the last vestige of independent civil society, the Buddhist masses. As protests rocked the streets, the CIA orchestrated a coup that brought down Diem, and replaced him with a rotating set of empty suits.
As Halberstam demonstrates again and again, American diplomacy was simply incapable of meaningfully changing the political culture of South Vietnam. New technological weapons like helicopters and APCs could provide a temporary advantage, but couldn't alter the fundamental dynamics of peasant political war. This book, written post '63 and published in 1965, predicted exactly what actually happened with the escalation. It seems like no one in power read it, and they certainly failed to understand its lessons.