It was a noble cause.
The French were fighting in Vietnam in 1950 not the US.
When Afghanistan jet fighters are fighting US jet fighters. When Afghanistan tanks are fighting US tanks. When Afghanistan warships are fighting US warships. When Afghanistan soldiers are fighting US soldiers. Then it will be like Vietnam. Right now, it just a law enforcement issue; finding terrorists, arresting them, or terminating them.
South Vietnam
The US wanted N. Vietnam to stop fighting in S. Vietnam.
US Servicemen had been fighting communists in South Vietnam since 1955.
It was fighting for democracy and against communism.
The US re-deployed from the place.
The containment of communism.
Eisenhower's Testerones level
To prevent the spread of communism.
The US has been fighting in Afghanistan longer it was fighting in Vietnam. It is the longest war in US history.
WACs & WAVEs did the same thing they did in WWII; supported the US fighting men. Primary functions were administrative and medical (nurses).