Westmoreland repeatedly rebuffed or suppressed attempts by John Paul Vann and Lew Walt to shift to a "pacification" strategy. Westmoreland had little appreciation of the patience of the American public for his time frame, and was struggling to persuade President Johnson to approve widening the war into Cambodia and Laos in order to interdict the Ho Chi Minh trail. He was unable to use the absolutist stance that "we can't win unless we expand the war". Instead, he focused on "positive indicators", which ultimately turned worthless when the Tet Offensive occurred, since all his pronouncements of "positive indicators" did not hint at the possibility of such a last-gasp dramatic event. Tet outmaneuvered all of Westmoreland's pronouncements on "positive indicators" in the minds of the American public. Although the communists were severely depleted by the heavy fighting at Khe Sanh when their conventional assaults were battered by American firepower, as well as tens of thousands of deaths in the Tet Offensive, American political opinion and the panic engendered by the communist surprise sapped U.S. support for the war, even though the events of early 1968 put the United States and South Vietnam into a much stronger military position.