Final answer:
U.S. involvement in Vietnam was characterized by extensive troop deployment and a prolonged conflict, while the Bay of Pigs invasion involved supporting anti-Castro Cubans in a brief and limited engagement.
Step-by-step explanation:
The U.S. Cold War involvement in Vietnam differed from its involvement in Cuba during the Bay of Pigs invasion primarily in the scale and nature of military engagement. In Vietnam, the United States committed large numbers of American troops and became extensively involved in a prolonged conflict, supporting the democratic South Vietnam against the Communist North with both military advisors and active battlefield engagement. In contrast, the Bay of Pigs invasion was a smaller-scale operation where the U.S., through the CIA, supported a group of anti-Castro Cubans in an attempt to overthrow the Cuban government, which was a short-lived and unsuccessful operation without widespread American troop deployment.