He later earned a doctorate from the University of North Carolina at Chapel Hill, writing a dissertation that he later turned into a widely acclaimed book, Dereliction of Duty: Lyndon Johnson, Robert McNamara, the Joint Chiefs of Staff, and the Lies That Led to Vietnam, published in 1997.



A 2006 article in the New Yorker that focused on McMaster's service during the Iraq War said the book "assembled a damning case against senior military leaders for failing to speak their minds when, in the early years of the war, they disagreed with Pentagon policies. The Joint Chiefs of Staff, knowing Johnson and McNamara wanted uncritical support rather than honest advice, and eager to protect their careers, went along with official lies and a split-the-difference strategy of gradual escalation that none of them thought could work. Dereliction of Duty won McMaster wide praise, and its candor inspired an ardent following among post-Vietnam officers."