When Robert McNamara accepted President Kennedy’s offer to serve as the United States’ eighth Secretary of Defense, the role was still new, a barely decade-old innovation emanating from World War II. As a young agency, the OSD was still defining its place in the national security decision-making landscape and, in so doing, trying to find the appropriate balance of power between civilian and military authorities. President Eisenhower had left the new administration with the Defense Reorganization Act of 1958, a congressionally mandated program for change at the Department of Defense. McNamara recognized its sweeping potential to pave the way for his bureaucratic revolutions as the longest-serving Secretary of Defense.

In many respects, as he confessed later in life, McNamara’s mistakes were mistakes of omission not commission. They were mistakes nonetheless. His mistakes raise important counterfactual questions. What if McNamara had inherited another model for civil-military relations? What if the State Department had been stronger? Could a counterinsurgency strategy have worked in South Vietnam? Could different funding arrangements in Washington have produced different outcomes? What if Johnson had been less of a New Dealer? What if McNamara had defined “loyalty” differently? What would President Kennedy have done?

The book provides a reassessment of Robert S. McNamara’s decisions during the Vietnam War. It situates him at the end of a historical process for the Office of the Secretary of Defense (OSD), a young agency that was still in flux and trying to define the proper balance between civilian and military advisors. McNamara’s concern for economic issues meant he resisted international commitments, in Vietnam and elsewhere. His idiosyncratic views on loyalty led him to self-censor and adopt public positions that were at odds with his private views. He ultimately became the spokesperson for a war that he had resisted. The book has benefited from a host of new sources, including McNamara’s papers at the Library of Congress, recently declassified Defense Department materials and the private diaries of his assistant for International Security Affairs, John T. McNaughton.

McNamara moved more forcefully than any of his predecessors in implementing civilian control over the military, with a contemptuous and domineering attitude toward the Joint Chiefs of Staff (JCS). His most important managerial innovations were designed to enforce “subjective control,” namely to impose civilian objectives and ideas on the military. The Draft Presidential Memoranda (DPMs) and the Planning, Programming and Budgeting System (PPBS) were designed to align military tools to civilian-defined foreign and economic policies. He worked closely with Secretary of State Dean Rusk to align military tools to the President’s foreign policy and with Secretary of the Treasury C. Douglas Dillon to ensure the Defense Department’s programs fit within a framework of fiscal discipline.