Answer:
Gulf of Tonkin incident.
Step-by-step explanation:
- The Gulf of Tonkin incident occurred after two US naval destroyers were attacked by the Vietnamese communist army in 1964.
- This incident led to the passage of the Gulf of Tonkin Resolution in August 7, 1964. It gave president John B Lyndon the power to take all necessary steps to retaliate any armed attack by the Vietnamese communist regime against the military of the United States.
- This incident led to the increase of American troop strength in Vietnam as the resolution aimed at preventing any large scale aggression or damage to the US military by Vietnam.