From Dereliction of Duty: Johnson, McNamara, the Joint Chiefs of Staff, by H. R. McMaster (HarperCollins, 2011), Kindle Loc. 227-39, 369-89:
Because the front line against Communism had not been drawn in Laos, South Vietnam would become the principal focus of U.S. policy in Southeast Asia. Under those circumstances Kennedy brought into his administration a man who would exert great influence over two presidents’ decisions to escalate American involvement in Vietnam.
Reeling from the wave of public criticism following the Bay of Pigs and aware of his increasingly troubled relationship with the JCS, Kennedy told his staff that he needed someone to be “my advisor to see that I am not making a dumb mistake as Commander in Chief.” To provide him with military advice and to coordinate the efforts of the White House staff, Defense Department, and intelligence agencies, the besieged president looked to former Army Chief of Staff Maxwell Davenport Taylor.
Max Taylor seemed the model of the soldier-statesman. Inspired by his Confederate grandfather’s Civil War tales, Taylor pursued a military career with great enthusiasm from an early age. When his sixth-grade teacher asked him to name his professional ambition, the young Taylor wrote “major general.” Twelve years later he graduated fourth in the West Point class of 1922. A talented linguist, Taylor later returned to the Military Academy to teach Spanish and French. During assignments in China and Japan, he became proficient in Japanese. It was, in part, his reputation as both a warrior and a scholar that made the general attractive to Kennedy.
The president privately acknowledged that Taylor’s responsibilities could easily have been performed by the Pentagon’s senior military men. He was not only dissatisfied with the Joint Chiefs’ advice but also frustrated by his inability to establish with them the kind of friendly rapport that he enjoyed with the rest of his staff and with many of his cabinet officials. To Kennedy generals and admirals were too formal, traditional, and unimaginative. Bundy confided to Taylor’s principal assistant that Kennedy “would never feel really secure” about the military until “young generals of his own generation in whom he has confidence” filled the top uniformed positions in the defense establishment. Bundy knew that it was important to Kennedy that the top military men be able to “conduct a conversation” with the president to give him a “feeling of confidence and reassurance.” Taylor would strive to satisfy the president’s need. Kennedy’s new personal adviser found the president “an amazingly attractive man—intelligent with a ready wit, personal charm, an ability to inspire loyalty in the people around him.” He soon cultivated a warm friendship with the president and his family.
Taylor knew that the Chiefs and the secretary of defense viewed him as a competing voice in national security issues. The retired general moved to head off potential animosities and assured his old friend Lemnitzer that he would be more of an ally than a source of competition. He told Lemnitzer that his “close personal relations with the President and his entourage” would help to ensure that the Chiefs’ advice reached the president.
When he arrived in Washington on April 22, Taylor’s first responsibility was to conduct an investigation of the decision to mount the Bay of Pigs invasion. Although he concluded that the Chiefs were “not directly responsible” for the misadventure, he criticized them for not warning the president more urgently of the dangers. When the administration sought military advice on narrow questions about the operation, the Chiefs gave competent answers but offered no overall assessment because “they hadn’t been asked.” Taylor concluded that relations between the commander in chief and the JCS had reached “crisis” level.