"Johnson did what modern American presidents are never supposed to do: refrain from seeking re-election. (Since World War II, only Harry Truman in 1952 has done likewise.) He feared that his health could not withstand four more years, but what really worried him was the Vietnam War and the divisions it had created. The war was not just a threat to his personal legacy; it was a threat to the very foundations of the liberal political order that he cherished so deeply and that had built so many middle-class American dreams."

On Nov. 29, 1967, President Lyndon Johnson announced that Robert McNamara, the secretary of defense, would leave his post to run the World Bank. “I do not know to this day whether I quit or was fired,” McNamara wrote decades later. “Maybe it was both."

In “The American War,” Washington Post Opinion columnist Alyssa Rosenberg interviews the filmmakers of the new PBS documentary, "The Vietnam War." Professor Fredrik Logevall, an adviser to the film, shares why Americans’ historical understanding of Vietnam is so limited to their own experiences.

"Historians, trained to take the long view but living in the here and now, have been struggling to make sense of Donald Trump's chaotic bid to win the presidency and thus become the commander-in-chief of the most powerful military force in the world."

"I think that he has on some level grasped the difficulties I mentioned a moment ago: the difficulties of counterinsurgency and nation building, the limits of American power. I think he has acted on the basis of those convictions. I think he has a fundamental faith in diplomacy, which I think is right. He understands that diplomacy and negotiations can be a very powerful tool in the tool kit of American strategists, and I think that he is exactly right. So I am appreciative of the fact and supportive of the fact that he has pursued negotiations with Iran most notably, also with Cuba."

Fredrik Logevall is the Laurence D. Belfer Professor of International Affairs and professor of history at Harvard Kennedy School, based at the Belfer Center. An expert on the history of international affairs, he was until recently a professor of history at Cornell University. He is the Pulitzer Prize-winning author of Embers of War: The Fall of an Empire and the Making of America’s Vietnam (Random House, 2012). In 2014, Logevall served as president of the Society for Historians of American Foreign Relations.

"...[T]he internal record makes clear that Kissinger and Nixon always saw foreign policy options through the lens of domestic politics. Confident of the fundamental security of the American homeland, they were willing to play politics with foreign policy, often with deleterious consequences."