Who: The Vietnam and USA troops. Later on Vietnam was involved in the war.
What: The war lasted 20 grilling years. In 1955, The USA entered the war. But the first USA troops started warfare in 1965. President Johnson's war plan was to help south Vietnam beat north Vietnam without trying to get involved much.
Where: the war took place in sour Vietnam.
When: the Vietnam war was fought between communists and north Vietnam between November 1st 1955-April 30.
Why: communists north veitnam was trying to conquer south Vietnam. In 1964 the north viet navy attacked the US navy over seas on Tonkin gulf. This created direct war between north veitnam and USA.
The war started in 1955 and lasted 20 years. The leader of north Vietnam wanted to make USA successful but USA didn't want communism running threw South Asia. USA wanted south Vietnam to be successful without getting involved but the plan didn't work.