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
