 Nixon's papers show that in 1968, as a presidential candidate, he ordered Anna Chennault, his liaison to the South Vietnam government, to persuade them to refuse a cease-fire being brokered by President Lyndon Johnson.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.