If the Soviet Union obtained and copied the AIM-9 during the early Taiwan Strait crises, how much would that help in Vietnam?
Short answerIt would be an improvement, but the first Sidewinder was too limited for the copy by itself to transform the later air war.
NotesThe original Sidewinder would improve on contemporary Soviet weapons. However, the early missile was far less capable than the versions fielded by 1980 or today. The effect on the later Vietnam War would therefore be real but limited rather than transformative.