<P> One major hallmark of McNamara's cost reductions was the consolidation of programs from different services, most visibly in aircraft acquisition, believing that the redundancy created waste and unnecessary spending . McNamara directed the Air Force to adopt the Navy's F - 4 Phantom and A-7 Corsair combat aircraft, a consolidation that was quite successful . Conversely, his actions in mandating a premature across - the - board adoption of the untested M16 rifle proved catastrophic when the weapons began to fail in combat . McNamara tried to extend his success by merging development programs as well, resulting in the TFX dual service F - 111 project . It was to combine Navy requirements for an Fleet Air Defense (FAD) aircraft and Air Force requirements for a tactical bomber . His experience in the corporate world led him to believe that adopting a single type for different missions and service would save money . He insisted on the General Dynamics entry over the DOD's preference for Boeing because of commonality issues . Though heralded as a fighter that could do everything (fast supersonic dash, slow carrier and short airfield landings, tactical strike, and even close air support), in the end it involved too many compromises to succeed at any of them . The Navy version was drastically overweight and difficult to land, and eventually canceled after a Grumman study showed it was incapable of matching the abilities of the newly revealed Soviet MiG - 23 and MiG - 25 aircraft . The F - 111 would eventually find its niche as a tactical bomber and electronic warfare aircraft with the Air Force . </P> <P> However, many analysts believe that even though the TFX project itself was a failure, McNamara was ahead of his time as the trend in fighter design has continued toward consolidation--the F - 16 Falcon and F / A-18 Hornet emerged as multi-role fighters, and most modern designs combine many of the roles the TFX would have had . In many ways, the Joint Strike Fighter is seen as a rebirth of the TFX project, in that it purports to satisfy the needs of three American Air arms (as well as several foreign customers), fulfilling the roles of strike fighter, carrier - launched fighter, V / STOL, and close air support (and drawing many criticisms similar to those leveled against the TFX). </P> <P> During President John F. Kennedy's term, while McNamara was Secretary of Defense, America's troops in Vietnam increased from 900 to 16,000 advisers, who were not supposed to engage in combat but rather to train the Army of the Republic of Vietnam . The number of combat advisers in Vietnam when Kennedy died varies depending upon source . The first military adviser deaths in Vietnam occurred in 1957 or 1959 under the Eisenhower Administration, which had infiltrated Vietnam, through the efforts of Stanley Sheinbaum, with an unknown number of CIA operatives and other special forces in addition to almost 700 advisers . </P> <P> The Truman and Eisenhower administrations had committed the United States to support the French and native anti-Communist forces in Vietnam in resisting efforts by the Communists in the North to unify the country, though neither administration established actual combat forces in the war . The U.S. role--initially limited to financial support, military advice and covert intelligence gathering--expanded after 1954 when the French withdrew . During the Kennedy administration, the U.S. military advisory group in South Vietnam steadily increased, with McNamara's concurrence, from 900 to 16,000 . U.S. involvement escalated after the Gulf of Tonkin incidents in August 1964, involving two purported attacks on a U.S. Navy destroyer by North Vietnamese naval vessels . </P>

In the late 1960s secretary of defense concluded that the united states could not win the war