From Wikipedia

The 10,000 Day War
Episode Three

 Days Of Decision

Richard Nixon had campaigned in the 1968 presidential election under the slogan that he would end the war in Vietnam and bring "peace with honor." However, there was no plan to do this, and the American commitment continued for another five years. The goal of the American military effort was to buy time, gradually building up the strength of the South Vietnamese armed forces, and re-equipping it with modern weapons so that they could defend their nation on their own. This policy became the cornerstone of the so-called Nixon Doctrine. As applied to Vietnam, it was labeled Vietnamization.

President Johnson in conversation with Chairman of the Joint Chiefs of Staff Earle Wheeler (center) and General Creighton Abrams (right).

Soon after Tet, General Westmoreland was promoted to Army Chief of Staff and he was replaced by his deputy, General Creighton W. Abrams. Because of the change in American strategy posed by Vietnamization, Abrams pursued a very different approach. The U.S. was gradually withdrawing from the conflict, and Abrams favored smaller-scale operations aimed at PAVN/NLF logistics, more openness with the media, less indiscriminate use of American firepower, elimination of the body count as the key indicator of battlefield success, and more meaningful cooperation with South Vietnamese forces.