Strauss and Howe (not Klein after all), called The Fourth Turnings, turnings being significant milestone events in a country or culture that kickstart in a fashion an era. Nutshell version: Pearl Harbor, Assassination of JFK, Reagan's Morning in America and 911. The eras brought on by these events are called with broad brush, using America as the nation of conern, a High, An Awakening, the Unravelling and Crisis. It is a way cool book, dealing as well with archetypes of heroes and visionairies and the like. A great read. I read it in '94 and we had no idea what would kickstart CRISIS, until of course 911. The marked eras last 18-20 years. Look it up.
https://www.fourthturning.com/