The United States involved itself in a hopeless fight against communism due to its prior commitment to a policy of containment. There were certain military and political objectives that were involved. There were also weaknesses within U.S. strategy, which contributed to the failure of American involvement. The American people were unsatisfied with the government's choices and questioned the purpose. The United States committed itself to something that was doomed to fail from the beginning, and it did. American participation was proven to be a waste of American time and lives.
The overarching political aim behind the United States' involvement in Vietnam was to contain the spread of communism in Southeast Asia. This American policy was called containment. It said that the U.S. should try to keep communism contained and prevent spread of the belief. The involvement basically was initiated during the Cold War, and it was also due to American fear of communism. .
To accomplish this aim, the United States supported an anti-communist regime known as the Republic of Vietnam in its fight against a communist take-over. South Vietnam faced a dual threat: a communist-led revolutionary insurgency within its own borders and the military power of its communist neighbor and rival, the Democratic Republic of Vietnam. Preventing South Vietnam from falling to the communists ultimately led the United States to fight a major regional war in Southeast Asia. The North Vietnamese regime, which received outside assistance from the communist great powers, the Soviet Union and the People's Republic of China, proved to be a strong opponent. .
There are still questions about the strategies of the United States. It seems as though some of the strategies were based upon political reasoning rather than foreign policy or military tactics. Politically, Kennedy and Johnson kept troops in Vietnam to keep communism from taking over during their term in office.