Why did the United States get involved in Vietnam?
The Soviet Union sent money to aid communist Vietnam.
The French agreed to divide Vietnam on the 17th parallel.
UN forces had begun reinforcing the South Vietnamese army.
Communist North Vietnam tried to reunify with South Vietnam by force.
The main reason the United States got involved in Vietnam was to prevent the spread of communism in Southeast Asia. The US government believed in the domino theory, which suggested that if one country in the region fell to communism, neighboring countries would also follow suit. The US saw the conflict in Vietnam as a crucial battleground in the larger Cold War between the capitalist West and the communist East, and therefore felt compelled to intervene to support the non-communist government in South Vietnam.
