Answer :
The gulf of tonkin gave the President of the United States (Lyndon B. Johnson) the right to use any military force that was deemed conventional without the declaration of war by Congress in Southeast Asia and to assist any army, whether legitimate or not. This started the rapid escalation from the Americans in the Vietnam War and their rapid warfare against North Vietnam.
Since You didn't put answer choices I decided to use my answer choices.
C) It allowed President Johnson to escalate the war by sending in ground forces and bombing North Vietnam.
That is your answer.
