The high-handed approach of the American government to contain internal military dissent proved to be a public relations disaster as well, culminating in the eventual withdrawal of troops. Noted historian Howard Zinn notes the following:
“…a black private in Oakland refused to board a troop plane to Vietnam, although he faced eleven years at hard labor. A navy nurse, Lieutenant Susan Schnall, was court-martialed for marching in a peace demonstration while in uniform, and for dropping antiwar leaflets from a plane on navy installations…. Two black marines, George Daniels and William Harvey, were given long prison sentences (Daniels, six years, Harvey, ten years, both later reduced) for talking to other black marines against the war.” (Allen, 2005)
Hence, in conclusion, it could be asserted that the causes that led to the American defeat were multifold. Some of the salient ones include the inability to understand the foreign primitive culture of the Vietnamese and underestimating their military organization skills. The growing unrest of the American public over the number of casualties and the ambiguity of the American motive were also important reasons. The guerilla warfare technique proved too difficult for the G.I.s to tackle. The growing lack of discipline and commitment of the American troops was another key reason for the defeat of the United States in the Vietnam War.
Christian G. Appy., Vietnam: The definitive oral history, from all sides., Viking Books. 2003.
Joe Allen, Vietnam: The War the U.S. Lost, From Quagmire to Defeat International Socialist Review Issue 40, March–April 2005.