1968 was the date the Cultural Revolution began. Americans are most familiar with Woodstock, but there were similar movements in Europe and, to a lesser extent, Japan. There were student riots in Paris that year. Charles de Gaulle fled to his home in the country at their height, because he didn't know how to deal with them. In Germany you had the rise of the Bader Meinhoff gang. In Italy there were similar terrorist groups.
Vietnam was the peg on which much of this revolutionary fervor hung. But to some degree it was just an excuse for something that was ripe to happen anyway. The Cultural Revolution was the logical outgrowth of late, decadent modernism, with it growing realization that the Age of Reason was not all that rational after all and that "progress" had led to Stalin, Hitler, and two world wars.
Later, Vietnam was blamed on Nixon, but it was Lyndon Johnson who presided over the turning point. No doubt one reason reporters turned against the war was their perception that Johnson had no intention of winning it. He micromanaged and tied the military's hands. The rot came from the head down.
Maybe that's why today's reporters are so obsessed with attacking the leadership. But the truth is that Bush has been an excellent leader. Cheney as been an excellent leader. Rumsfeld has been an excellent leader. Unlike Johnson they have been determined to do things right and to win. The Vietnam generation of reporters went overboard in the end, but they had genuine issues to object to. The Iraq generation of reporters have nothing but bad faith.