"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."