Wrongful American Involvement In Vietnam

The United States removed its troops out of Vietnam knowing that they had made a huge mistake. Thousands of American troops never came back, with billions of dollars down the drain. Their ultimate goal of anti-communism was a failure, as a year later the north engulfed the South and created a unified communist nation of Vietnam. With every goal of the US in the war ending in failure, we must look back and see why and how Vietnam became such a failure.
The entire war in Vietnam was poorly planned, fought, and executed. For starters, we had no concrete goal in the war. US soldiers were sent to Vietnam on the vague goal of "stopping communism". Soldiers were sent to patrol the country side, defending South Vietnam from communists. No cities were to be captured, no  visible enemy to destroy. With the United States unable to invade the communist north without Soviet intervention, there was no way to win the war. The United States had no way of victory. With their goal of the elimination of communists, United States marines and soldiers were sent into the jungle to kill an unseen enemy. A communist and farmer look exactly the same, and US soldiers many times were unable to kill an enemy until they shot first. As new Secretary of Defense Robert McNamara came into office, he asked questions about the Vietnam war. He asked what our goal was in Vietnam and he received an answer of "we don't know". When he asked how many more troops had to die before we left he received the same answer. When even the highest level of US military leadership doesn't know the goal or when the war should end, there is a fundamental problem. Only after huge public opinion became against the war, did the United States begin to pull out of Vietnam.
Source: http://www.vietnam.ttu.edu/resources//mcnamara/