It is worth remembering that Britian was the occupying power in Vietnam before the arrival of America and the return of the french. And also, that Americas involvement stems from a meeting with Ho Chi Min and a Majory Pattie of the OSS, Pattie said that Ho was a man that they could work with! But the actual American invovlement in war is worth a whole forum on its own. I did not like the website as it was too vauge in places and seemed to put emphasis on the wrong things! Also, tactical nuclear bombs were not a vivable option in Indo-china, the first real mention was made by Richard Nixon in his Memoirs; about Operation Vulture which had been devised by the Joint Chiefs. the plan allowed for the droppoing of three tactical nuclear weapons around Dien Bien Phu, but Lyndon Johnston and others including JFK vetoed the project.
Consequences within Indochina of the Fall of Dien Bien Phu '54. https:/www.mtholyoke.edu/acad/intrel/pentagon/doc40.htm