If there was one individual who had more impact than anyone else on the Defense Department's role in foreign affairs, it was Robert S. McNamara. Appointed by President John F. Kennedy in 1961, McNamara served as secretary of defense until 1968, when the stalemated war in Vietnam prompted his resignation. Throughout most of his tenure, McNamara was an ardent advocate of American involvement in Southeast Asia and a key figure in planning and prosecuting the war. Indeed, in a very real sense, foreign policy toward Southeast Asia during these years was a product of the Pentagon, which was largely responsible for orchestrating the war. Victory, however, proved elusive, and as time passed McNamara saw his self-confidence and credibility steadily erode. Disillusioned and frustrated, he left office counseling withdrawal and stepped-up efforts at a negotiated settlement.
Yet the frustrations of Vietnam and their ripple effects were only part of the McNamara story. Indeed, without Vietnam, McNamara's tenure would probably be remembered as a period of extraordinarily positive accomplishments, from improved management of the Pentagon to reduced reliance on nuclear weapons and the initiation of the first serious efforts at strategic arms control. Outwardly, McNamara was an unlikely candidate to play such a major part in foreign affairs. A former president of Ford Motor Company, he seemed destined at the outset of his tenure to follow in the footsteps of Wilson and McElroy and become a business manager of the Pentagon. That he emerged instead as a pivotal figure in foreign policy was as much a product of his approach to the job of secretary of defense as it was the unique circumstances in which he found himself. The result was a far more active and involved Defense Department at all levels of the policy process, including especially high-level decision making.
Much of the power and authority that the Pentagon wielded under McNamara accrued by default rather than by design. President Kennedy had little use for the elaborate National Security Council system developed under Truman and Eisenhower, and in its place he substituted a slimmed-down version with limited capabilities for independent policy analysis. Further, he discontinued the practice of conducting elaborate annual national security reviews and expected the State Department to exercise primary responsibility for developing and coordinating policy. The weak link in this system proved to be Dean Rusk, Kennedy's choice as secretary of state. Although affable and intelligent, it soon became apparent that Rusk lacked the temperament and drive to carry out the job entrusted to him. Eventually it fell to McNamara to fill the void.
For the record, McNamara accepted the conventional wisdom that defense policy derived from foreign policy and that the Pentagon's function was to serve and assist the State Department. But in day-to-day practice, McNamara, with Kennedy's blessing, generally followed his own lead. The approach McNamara adopted was to supply his own foreign policy guidance, which he included with each budget submission to the president and in his annual reports (termed "posture statements" to give them more prestige) to Congress. Going beyond a purely military rationale, McNamara's posture statements offered broad justification for new and ongoing defense programs based on the manner in which they would contribute to furthering U.S. foreign policy objectives. "It was essential," McNamara recalled in an interview, "to begin with a discussion of foreign policy because that had to be the foundation of security policy." Although the State Department routinely submitted advice and comments, its views often arrived too late in the budget process to be reflected in the final documents forwarded to the White House and Capitol Hill.
For support, McNamara assembled a highly skilled and talented staff, dubbed the "whiz kids," who implemented a host of far-reaching administrative and managerial reforms. Some of the changes they and McNamara made, including the extensive use of computer-driven "systems analysis" models and mission-oriented budgeting techniques, proved controversial and hard for the military services to swallow. But there is no doubt that they gave the secretary a stronger and firmer hand, both in running the department and in projecting his influence into foreign policy. Moreover, they liberated the secretary from having to draw as often on the Joint Chiefs of Staff and the military services for advice and analysis of politico-military problems. By the middle of the decade, McNamara had at his fingertips the most sophisticated and effective organization for analyzing and managing politico-military affairs that Washington had yet seen. Whether, as some critics charged, McNamara's reforms invited the further "militarization" of American foreign policy is debatable. Within the Pentagon, McNamara exercised an unprecedented degree of civilian control over the military and routinely used civilians in International Security Affairs and in other key positions to perform chores previously reserved for the services or the JCS. If this was militarization, it was most definitely of the civilian-shaded variety.
All the same, the tendency to apply military solutions to serious problems abroad grew steadily during the 1960s. This was true not only in Southeast Asia but also in dealing with incidents in Cuba, Berlin, the Dominican Republic, and other Cold War flashpoints. During the late 1940s and 1950s, U.S. military power had relied in the first instance on the presumed deterrent effects of nuclear retaliation to cope with the threat of communist aggression. But by the 1960s, with the United States and the Soviet Union approaching effective parity in strategic nuclear power, it was no longer realistic to threaten wholesale nuclear destruction. Seeking a more credible posture, McNamara seized on the doctrine of flexible response as a means of providing the president with a wider range of options for dealing with critical international problems.
The essence of flexible response was a varied mixture of forces allowing a greater choice in military actions, with emphasis on containing any conflict below the level of a nuclear exchange. Developed initially with Europe in mind, McNamara hoped that flexible response would provide an alternative to the all-or-nothing mentality that then dominated NATO strategic planning. To achieve the desired posture, he urged stepped-up procurement of conventional forces and changes in the programmed use of nuclear weapons to allow for a "pause" or "firebreak" between conventional conflict and a larger war. European critics countered that such a strategy would be prohibitively expensive and that it would under-mine nuclear deterrence and increase the risk of a conventional conflict. But with patience and perseverance, McNamara gradually brought the Europeans around. Adopted by NATO in 1967, flexible response was, on paper at least, a major break with the past, although in practice its effects were somewhat negated by the reluctance of the European allies to commit themselves to a sustained conventional buildup. Even so, flexible response remained NATO's governing strategic doctrine for the duration of the Cold War and into the early 1990s.
Another of McNamara's contributions was to help institutionalize a more serious attitude within the Defense Department toward strategic arms control and disarmament. What prompted McNamara's involvement was mounting evidence by the mid-1960s that the Soviet Union had embarked upon the deployment of two prototype antiballistic missile (ABM) systems, thus putting pressure on the United States to respond in kind. Dubious of the technologies involved, McNamara sought to avoid a costly and perhaps futile ABM competition by proposing negotiations with the Soviets to curb both offensive and defensive strategic weapons. Although the Joint Chiefs remained skeptical about whether such talks would amount to much, they agreed with McNamara's basic premise that the strategic arms competition was getting out of hand and that restraint on both sides could serve a useful purpose. This was a dramatic turnaround from military thinking in the 1950s, and it went far toward paving the way for the Anti-Ballistic Missile Treaty and other arms control accords growing out of the Strategic Arms Limitation Talks (SALT) between Washington and Moscow in the 1970s.
Outside Europe, flexible response played a less conspicuous role in shaping American foreign policy. The escalating conflict in Southeast Asia defied the conceptual models that McNamara was so fond of applying, and by 1966 the United States found itself engaged in a war of attrition with North Vietnam. Nevertheless, McNamara approached the war as he generally approached other problems, seeking to reduce it to quantifiable proportions. Knowing McNamara's preferences, subordinates tailored programs and recommendations accordingly, stressing systems analysis techniques over less quantifiable means of assessing the war's progress and possible outcome. The use of statistical models, whether involving kill ratios, construction rates, frequency of incidents, or other indicators, gave a distorted picture of the war, often because the U.S. command in Saigon and the South Vietnamese government, knowingly or otherwise, provided erroneous data. By the time McNamara realized what was happening, the United States was so committed to prosecuting the war that there was no turning back without doing what he and President Lyndon B. Johnson considered serious damage to U.S. prestige and credibility.
McNamara's tenure at the Defense Department thus left a mixed legacy. While there was progress in curbing the menace of nuclear war, the United States found itself plunging ever more deeply into an ill-advised and ill-conceived conflict in Southeast Asia. McNamara demonstrated that a strong-minded and strong-willed secretary of defense could exercise enormous influence on American foreign policy. However, his immediate successors were leery of following suit.