Why did president eisenhower believe it was important for the united states to provide aid to vietnam?

President Eisenhower believed that if Vietnam were to be turned into a communist country that would give motivation for other countries to turn to communism, this was known as an example of the domino theory. There was a lot of disagreement in Vietnam that caused themselves to split due to communism.  North Vietnam wanted to conquer South Vietnam to form a communist Vietnam.  President Eisenhower feared this which caused him to make the decision of aiding South Vietnam in order to prevent North Vietnam from taking over South Vietnam and forming the two into a communist country which would steer other countries into communism.