In 1965 President Johnson immediately use the story of the golf of Tonkin resolution to

Begin sustained bombing of North Vietnam

Explanation:

On August 7, 1964, Congress declared the Gulf of Tonkin Resolution, allowing President Johnson to take any steps he thought were important to counter and to encourage the preservation of international peace and protection in southeast Asia. North Vietnamese army torpedo boats bombed the USS Maddox while the warship was in international waters in the Gulf of Tonkin.