During the 1990s, two amateur historians, Neil Howe and the late William Strauss, developed a new theory of American history in two books, Generations: the History of America’s Future(1991), and The Fourth Turning: An American Prophecy (1997).They identified an 80-year cycle in American history, punctuated by great crises that destroyed an old order and created a new one.

Though their theory is not widely taught in colleges or discussed in the media, Strauss and Howe may well play a major role in Donald Trump’s administration. Stephen Bannon, the former head of Breitbart News who has been appointed Trump’s chief strategist in the White House, is very familiar with Strauss and Howe’s theory of crisis, and has been thinking about how to use it to achieve particular goals for quite a while. I know this because Bannon interviewed both Neil Howe and myself in 2009 while he was making a documentary film about the ongoing financial crisis. The film, called Generation Zero, discussed those ideas in some detail.

Bannon focused on the key aspect of their theory, the idea that every 80 years American history has been marked by a crisis, or “fourth turning,” that destroyed an old order and created a new one: The great crises identified by Strauss and Howe included the era of the American Revolution and the Constitution (1774-1794); the Civil War and its immediate aftermath (1860-68); and the Depression and the Second World War (1929-45). Doing the math, they predicted another great crisis sometime in the first 15 years of the 21st century.

Strauss and Howe’s major prediction has now obviously come true: Few would deny that the U.S. has been in a serious political crisis for some time, marked by intense partisan division, a very severe recession, war abroad and, above all, a breakdown in the ties between the country and its political establishment.

I was one of very few professional historians to become interested in the work of Strauss and Howe, and I incorporated their insights into books on the origins of the Vietnam War and Franklin Roosevelt’s role in leading the nation into World War II. I have also incorporated their theory into analyses of European history and current events. I must admit that I did not know exactly what I was getting into when Bannon, who was then working at the conservative group Citizens United, contacted me to ask me for an interview, but I appreciated any chance to discuss Strauss and Howe’s ideas and the crisis that was by then indisputably upon us. Bannon is both intelligent and charismatic, and he clearly enjoyed our interview as much as I did. In the finished film, he used my interview perfectly fairly, without attempting to give it his own extreme right-wing slant. ...