Their goal was to fight and Vietnam and win, as in any other war for the US. This was because of something very important called the Domino Effect, created by Dwight D Eisenhower, which stated that if one country adopted communism, other countries surrounding it and eventually the world would start too.
The US couldn't have communism spread. That's why we were enemies with the Soviets and created a trade embargo on Cuba in 1960. Our goal was to get rid of communism once and for all.
However, on March 29th, 1973, when President Nixon withdrew all remaining troops from Vietnam, leaving America's first defeat, the Domino Effect could have happened and been quite bad. However, it did not spread around Indo-China, and few countries use communism today.
