Name 3 reasons why the USA got involved in the Vietnam war and give a detailed explanation for each.

Here are three reasons the U.S. got involved in Vietnam:
1.  The domino theory--this theory refers to how if one nation is taken over by Communists, then the others around it will also.  Kennedy's defense strategy referred to containment of Communism--not to let the Communists take over any more countries.  This meant fighting what America thought was Communist aggression anytime, anywhere.  
2. America needed to look strong in front of its allies.  Western European leaders constantly worried about Soviet aggression.  If America let South Vietnam fall to the North, then Western Europe may feel as though America could not protect them either.  South Vietnam soon became a symbol of America's ability to fight communism, and the U.S. needed to prove to Europe that it was the dominant superpower.  At the time many in American government thought that Communism was controlled by the Kremlin directly--later evidence has proven that this was not the case, even though North Vietnam received weapons and money from the Soviet Union.  
3. The Gulf of Tonkin Resolution--This one is probably the greatest of them all, because after 1965, America sent more than advisers and monetary aid to South Vietnam--it sent ground troops and air support.  The U.S.S. Maddox was carrying out a simulated radar attack on Hanoi in order to test the city's defenses.  Hanoi, understandably, sent a submarine to attack the Maddox.  While the simulated attack was not published in American news, the North Vietnamese attack was publicized, and many in America thought that a war against North Vietnam was the appropriate response.