McNamara, Clifford and the Burdens of Vietnam, 1965–1969, volume VI in the newly-named Secretaries of Defense Historical Series, covers the incumbency of Robert S. McNamara, as well as the brief, but significant, tenure of Clark M. Clifford. McNamara’s key role in the ever-deepening U.S. involvement in Vietnam between 1965 and 1968 forms the centerpiece of the narrative. During these years, Vietnam touched every aspect of Lyndon B. Johnson’s administration, determining budget priorities, provoking domestic unrest, souring relations with NATO, and complicating negotiations with the Soviet Union. McNamara’s early miscalculations about Vietnam became the source of deep disappointments. Relations with the Joint Chiefs of Staff, never good, frayed almost to the breaking point as McNamara repeatedly rejected military advice in favor of his civilian experts. McNamara’s carefully crafted plans failed, his frustrations grew, and he became estranged from the President. His private attempts to check the war’s momentum contradicted his public statements supporting the military effort and tarred McNamara as a hypocrite. McNamara’s successor, Clark Clifford, arrived with a reputation as a hawk, but focused most of his effort on extricating the United States from Vietnam. McNamara and Clifford presided over the Department of Defense during momentous and dangerous times. Vietnam was one of a series of wars, emergencies, and interventions involving U.S. interests. Intervention in the Dominican Republic, declining U.S. prestige and power in Europe and NATO, war in the Middle East, heightened tensions on the Korean peninsula, arms control talks with the Soviet Union, and violent protests at home competed for attention. Overseeing the Vietnam War and contending with these complex policy issues taxed even McNamara’s enormous energy and brilliant intellect as he struggled to manage DoD programs. His long-cherished cost-cutting programs fell by the wayside; his favored weapons systems were swept aside; his committed efforts to limit strategic arms faltered; and his reputation was permanently tarnished. McNamara, Clifford and the Burdens of Vietnam highlights the interaction of McNamara and Clifford with the White House, Congress, the JCS, the State Department, and other federal agencies involved in policy formulation. The two secretaries attempted to impose order while fighting a war whose cost of winning became as morally prohibitive as the price of losing.