The Watergate crisis which so undermined the credibility of Richard Nixon actually enhanced the credibility of the Kissinger foreign policy. First, Kissinger himself became a hero by default, an intelligent, occasionally witty man only peripherally involved with the cruder forms of espionage in which the rest of the Nixon entourage had specialised, who seemed unable to fail. But, more important, the barrage of Watergate revelations reinforced public cynicism. To a considerable extent the public accepted Nixon's defence. In foreign policy at least governments are duplicitous.
Crime is a traditional instrument of rule.
The liberal innocence which was at the heart of Much of the Vietnam protest is gone. The patriotism which took the rhetoric of freedom seriously has largely evaporated and people are both confused and numb, an ideal state of affairs for carrying on a Metternichean foreign policy.