Why did the US send troops to Vietnam?

Answer 1

The first US Military personnel arrived in Saigon in 1950 to assist the French in their war against the communist-led Viet Minh nationalists in the north. After independence and partition in 1954, the first US combat troops arrived in 1965 to support the military regime in South Vietnam against a communist-led insurgency supported by North Vietnam.

Answer 2

Believe it or not, there was a time when communism was considered to be a threat to the world. The communist nations vowed to destroy all non-communist nations, and non-communist nations, strangely enough, believed them.
The result was, that non-communist nations put together a pact; call it an agreement if you will. The agreement was that if communism attacked any of the members of the pact, the rest would step in to defend them.
It was a noble gesture, but unfortunately many of the nations of the pact failed to step in during the Vietnam War.

Answer 3

Prior to 1964, it wasn't either clear or possibly "confirmed" that the army of North Vietnam was commencing combat in the "Republic of South Vietnam." Just fighting local guerrillas (Viet Cong) seemed to be the norm. After the Tonkin Gulf incident, it was clear then...kind of hard to hide Torpedo Boats on the surface of the water (couldn't blame the VC for that attack). Now that North Vietnam clearly attacked the US Navy, the US opened "conventional" counter-attacks upon North Vietnam. The Tonkin Gulf "Incident" was the signal to commence open hostilities on each other (US vs North VN).

Answer 4

Presidents in both parties continued to send troops and supplies to fight in Vietnam because they feared the spreading of communism. Many of them also remembered Hitler from Germany and the atrocities that he committed.

Answer 5

South Vietnam was our ally and the US did not want the communist N. Vietnam to conquer them. The whole Cold War era thing was wack!