As President Johnson was urged by his closest foreign policy and defense advisors to initiate a sustained bombing campaign against North Vietnam during the winter of 1964–1965, Ball forcefully warned Johnson against such an action. In a February 24, 1965, memorandum he passed to the President through his aide Bill Moyers, Ball provided an accurate analysis of the situation in South Vietnam, and of the US stake in it, as well as a startlingly prescient description of the disaster any escalation of American involvement would entail. Urging Johnson to re-examine all the assumptions inherent in the arguments for increasing US involvement, Ball stood alone among the upper echelons of Johnson's policymakers when he attacked the prevailing notion, virtually unquestioned at the time in Washington, that America's fundamental strategic interest in escalating the conflict was in protecting US international prestige and the reliability of its commitments to allies.