James Clapper met Donald Trump for the first time on the morning of January 6, in a conference room at Trump Tower. Clapper, a retired three-star general, grew up in a military family and volunteered for two tours in Vietnam. Trump got five deferments: four for college, one for bone spurs. Clapper avoids scrutiny. Among his staff, he earned the nickname Grumpy Cat for his habit of scrunching up his weathered face during interviews and congressional hearings. Trump has a face optimized for broadcast, a Kabuki mask of synthetic emotion. He would hardly exist were it not for television. Despite these differences, the two men seemed to hit it off. There was no hint of how Trump would behave over the months that followed, diminishing both his office and his country to the point that Clapper would do something drastic, something that he never believed he would do—condemn a sitting president. Clapper remembers Trump at that first meeting as friendly and solicitous, flattering him with compliments. As Obama's director of national intelligence, Clapper had been tasked with investigating the role that Russia might have played in Trump's victory. He'd come to Trump Tower, with a group that included then FBI director James Comey, to brief the president-elect on the intelligence community's findings: that Vladimir Putin had attempted to intervene in the election, and in Trump's favor. At the time, Trump seemed to take the news well. "It was a professional exchange," Clapper told me.

As the meeting wrapped up, Comey stayed behind to share with Trump a bit more. He explained that a "dossier" full of salacious allegations linking Trump to Russia had been circulating widely around Washington for some time. "The main point was to warn him that it was out there," Clapper said. Days later, on January 10, BuzzFeed published 35 pages of the dossier. Suddenly, the Donald Trump who'd been so collegial turned into a very different man.

In Trump's mind, there had to be a connection between the January 6 briefing on the dossier and its January 10 publication by BuzzFeed. "Intelligence agencies should never have allowed this fake news to 'leak' into the public," he tweeted. "One last shot at me. Are we living in Nazi Germany?" Later that day, he compared American intelligence agencies to the Gestapo.

Clapper called up Trump to try to work things out. On the phone, according to Clapper, Trump asked him to put out a statement saying that it was bunk. Clapper refused. Without knowing the dossier's sources, there was no way to evaluate it. And at least one element from the document was true, Clapper told me, "the considerable animus Putin had for the Clintons. That we had from other sources."

The feud with the intelligence community got worse after Trump gave a speech at the CIA's Memorial Wall, where more than 100 fallen officers are honored with stars etched into stone. Trump filled the room with supporters and rambled on about the size of his inaugural crowds. "He kind of used it as a prop," Clapper told me, likening the Memorial Wall to the Tomb of the Unknown Soldier at Arlington.