When there is no external threat, there is less incentive to hang together. The bigger the threat, the more people cohere. The immediate aftermath of 9/11 was the high point of American unity. We have just reached the high point of American fragmentation.

I lived most of my life in the Cold War. There was a clear external threat. When that ended, societies inclined toward narcissism. The tribal got the upper hand. The selfie is the image of the zeitgeist. Choices became overwhelming in their multitude. Noise increased.

It’s been a long dissolution, punctuated with mistakes. Decline relative to other powers made Americans more desperate. They’d grown used to the century being theirs. Then they were thrust into another one that was not theirs. They came under attack.

Disorientation set in. In the end they sent a shrieking maniac to the White House.

President Trump is disturbed and growing more so. When he feels cornered, his symptoms run wild. As a narcissist, the thing he finds most intolerable is any suggestion that he cannot get away with whatever he wants. So he tweets: “IT WAS A PERFECT CONVERSATION WITH UKRAINE PRESIDENT!”