HHow were the policies and/or attitudes of the presidential administrations from Eisenhower to Nixon toward the Vietnam conflict different or similar?

Read and analyze the documents on American policy in the Vietnam War from the Eisenhower through the Nixon administration and explain in your paper the reasons for American involvement in the war. Why did government officials feel it necessary to defend South Vietnam? What did they fear if the South lost? In other words, why was the North such a threat? How were the policies and/or attitudes of the presidential administrations from Eisenhower to Nixon toward the Vietnam conflict different or similar?  In formulating your answer you must use at least 8- 10 total documents and a minimum of two documents from each presidential administration.