Red China had entered the Korean War in 1950-1953. As a result of that experience, the US went out of it's way to avoid any involvement of either the Soviet Union or Red China in the Vietnam War. Red China had entered the Korean War after the US/Allied counter-attack had invaded NORTH Korea all the way to the Red Chinese border. They would most probably do that it again, if the US/Allies invaded North Vietnam all the way to the Red Chinese border.
AnswerThe US had won the war. This was between USA and Russia to see who had a stronger military. Near the end of the war Russia's government collasped and they could not fund the military to make stronger weapons. But this was not a real war with combat.
There are a number of American History books that address this subject, and here are a couple of books I know about, which deal specifically with the anti-war movement: "An American Ordeal" by Charles DeBenedetti and "Telltale Hearts" by Adam Garfinkle. Also, most libraries have microfilm of the New York Times, which covered the anti-war movement, as did the Boston Globe, Washington Post, etc. There are also several individual memoirs-- Todd Gitlin's "The Whole World is Watching" is a good one (Gitlin was a war protester in college; today he is a sociologist), as is James Carroll's "An American Requiem" (he and his dad vehemently disagreed on the war-- he was an anti-war priest and his dad was in the military!).
Technologically plus a navy plus a much larger airforce, but in personal weapons, not really
Vietnam, which is in southeast Asia.