Our advisors were helping the French and we got sucked into it
The same reason the US started fighting : POLITICIANS. Politicians in general and liberal politicians in particular.
Stop communist aggression.
contain communism
actual fighting never reached Hanoi. When the U.S pulled out of Vietnam the South quickly started crumbling and surrendered before fighting ever reached their capital.
When the Vietnam War started, the world was in the grip of the Cold War. The United States was worried about the possible spread of Communism in Southeast Asia. We felt that we needed to act to prevent this.
In Vietnam European nation Great Britain tried to reassert their colonial. They also tried to claim Indochina.
The country of Vietnam had divided into communist North Vietnam and democratic South Vietnam, and was fighting a civil war to determine if the country would be reunified as a communist nation, or if it would remain a divided nation. Untimately, North Vietnam prevailed.
South Vietnam
North Vietnam started the war against South Vietnam; the US went to the aid of the South.
Air war North Vietnam. Ground war South Vietnam.
North Vietnam/VC vs allies
Vietnam and Cambodia