A number of reasons:
- Domino Theory
- Stop spread of communism
- USA thought Ho Chi Minh wanted to spread communism
- Help France
- USA believed Vietnam were taking orders from USSR (Stalin)
- Truman Doctrine
The fear of being invaded was not a justification for the increase in US involvement in Vietnam. The US withdrew from Vietnam in 1975.
A peninsula (such as Korea) can be patrolled and controlled by the US Navy (as was done in the Korean War 1950-1953). Vietnam had two countries (officially neutral in the war), Laos & Cambodia bordering N & S Vietnam's left (west) side. The Ho Chi Minh Trail went thru those countries (mostly Laos). The US would have had to involve Laos & Cambodia; WIDEN the war, in order to destroy/occupy the Ho Chi Minh Trail. This action could possibly involve Red China or the Soviet Union. Red China DID ENTER the Korean War when US/Allied forces invaded NORTH Korea during the Korean War. The US did not want to widen the Vietnam War. This is Why Vietnam had to be fought as a "Limited War." Limited by restrictions on Where it could be fought, and How it could be fought.
After the US withdrew from Vietnam the Vietcong came into power. South Vietnam fell under communist rule by the Vietcong.
The US is NOT at war with Iraq. The US was at war with North Vietnam.
The United States did get involved in the Vietnam war because of communism in Vietnam.
bombs
When you're drafted, no decision is involved.
The US never invaded Vietnam.
South Vietnam was considered an ally of the US.
US Military personnel were in Vietnam from 1955 thru 1975.
See: Vietnam
Vietnam
The US was concerned about the development of Communism in Vietnam
We were at war with Vietnam because they disagreed with us about something.
The French were fighting in Vietnam in 1950 not the US.
The fear of being invaded was not a justification for the increase in US involvement in Vietnam. The US withdrew from Vietnam in 1975.
The US wanted N. Vietnam to stop fighting in S. Vietnam.