All good points
Especially the fear of winning! We fought vietnam with the goal of tie or stalemate as occurred in Korea. What an idiotic policy that was!
America has had numerous military successes since 'Nam because of the lessons we learned there. Panama, Iraq, Haiti, Bosnia, Kosova, and now Afganistan.
Another difference between 'Nam and Afganistan: In 'Nam most of our troops were stoned half the time. Now that there is extensive drug testing in the armed forces that is no longer the case.