Pls help Why did the United States get involved in the Vietnam War?

Define: Domino Theory

Which amendment lowered the voting age? WHY?

1. The United States got involved in the Vietnam conflict keep communism from spreading throughout Southeast Asia.

2. A theory that if One country is taken over by an expansionist especially Communist neighbour party or the like the nearby nations will be taken over 1 after another.

3. The 26th ammendment prohibits the states and the federal government from using age as a reason for denying the right to vote to citizens of the United States who are at least eighteen years old.

Hope this helps

no, to many things have came in to factor