The correct answer to this open question is the following.
Secretary of Defense Robert McNamara and other top advisors believed that the U.S. needed to increase its military presence in Vietnam in order to defeat the communists. The measure that was passed by Congress and authorized the use of military force in Vietnam was the Gulf of Tonkin Resolution.
The Gulf of Tonkin Resolution led to the escalation of American troops in the War of Vietnam. It gave the President of the United States the ability to send troops without the specific Congress' approval.
On August 7, 1964, Congress passed the Gulf of Tonkin Resolution. It permitted President Lyndon B. Johnson to maintain peace in Southeast Asia.
Robert S<span>. </span>McNamara<span>. Was the </span>secretary<span> of </span>defense<span> under Kennedy. He helped develop the flexible response policy. He was against the war in </span>Vietnam<span> and was removed from 1964 Congressional resolution that authorized President Johnson to commit </span>US troops<span> to south </span>vietnam<span> and fight </span>a<span> war against north </span>Vietnam<span>.</span>
