Final answer:
The US went to war in Vietnam to prevent the spread of communism, and the Gulf of Tonkin Incident provided a reason for President Lyndon B. Johnson to enter the war.
Step-by-step explanation:
The two true statements about US involvement in the Vietnam War in the 1960s and 1970s are:
- The US went to war in Vietnam to prevent the spread of communism. This was a key reason for the US involvement in the war, as they feared the Domino Theory, which suggested that if one country fell to communism, neighboring countries would also fall.
- The Gulf of Tonkin Incident in 1964 provided a reason for President Lyndon B. Johnson to enter the war. The attack on the US Navy by the North Vietnamese gave Johnson the justification to escalate US involvement in Vietnam.
Learn more about US involvement in the Vietnam War