Had President Kennedy not pledged the nation to bear any burden, meet any hardship, support any friend, and oppose any foe to assure the survival and… - William Westmoreland

The enemy had achieved in South Vietnam neither military nor psychological victory. For the South Vietnamese the Tet offensive served as a unifying catalyst, a Pearl Harbor. Had it been the same for the American people, had President Johnson discerned the same support behind him that Thieu did behind him, and had he acted with forcefulness, the enemy could have been induced to engage in serious and meaningful negotiations. Unfortunately, the enemy scored in the United States the psychological victory that eluded him in Vietnam, so influencing President Johnson and his civilian advisors that they ignored the maxim that when the enemy is hurting, you don't diminish the pressure, you increase it.

Forced in January 1973 by American pressure to to accept a cease-fire agreement that left well over 100,000 North Vietnamese troops inside South Vietnam and free access for tens of thousands more, South Vietnamese leaders surely had reason to believe that if their enemy seriously violated the agreement, the United States would interfere. Yet that was not to be. In the face of that grave psychological blow for the South Vietnamese, it required no military genius to assure South Vietnam's eventual military defeat.

In the renewed war in South Vietnam beginning in the late 1950s, the considerable success that Giap and the Viet Cong enjoyed was cut short by the introduction of American troops. In the face of American airpower, helicopter mobility, and fire support, there was no way Giap could win on the battlefield. Given the restrictions they had imposed on themselves, neither was there much chance that the Americans and South Vietnamese could win a conventional victory; but so long as American troops were involved, Giap could point to few battlefield successes more spectacular or meaningful than the occasional overrunning of a fire-support base. Yet Giap persisted nevertheless in a big-unit war in which his losses were appalling, as evidenced by his admission to the Italian journalist Oriana Fallaci that he had by early 1969 lost half a million men killed. Ruthless disregard for losses is seldom seen as military genius. A Western commander absorbing losses on the scale of Giap's would have hardly lasted in command more than a few weeks.