Donald Trump’s defense secretary called him “a madman in a circular room screaming” and stayed away from the White House, a new book quotes a senior Trump aide as saying regarding the man now facing 88 criminal charges but set to be the Republican presidential nominee for a third successive election. “Anybody with sense – somebody like Mattis or Tillerson – they immediately shunned and stayed away from Trump,” Tom Bossert, formerly homeland security adviser to Trump, tells George Stephanopoulos in the ABC News anchor’s new book, The Situation Room: The Inside Story of Presidents in Crisis. “I mean, you couldn’t get Mattis into the White House,” Bossert says. “His view was, ‘That’s a madman in a circular room screaming. And the less time I spend in there, the more time I can just go about my business.’” Stephanopoulos’s book is a survey of how presidents have used the White House Situation Room, “the epicentre of crisis management for presidents for more than six decades”. Co-written with Lisa Dickey, a prolific ghostwriter who has also worked with the first lady, Jill Biden, and the governor of Michigan, Gretchen Whitmer, the book will be published next week. The Guardian obtained a copy. James Mattis, a retired US Marine Corps general, was Trump’s first defense secretary. Rex Tillerson, an oil industry executive, was Trump’s first secretary of state. Both were among so-called “adults in the room” who famously sought to contain Trump. Mattis’s frustrations and ultimate opposition to Trump’s re-election are widely known. Tillerson was reported to have called Trump a “fucking moron”. Trump fired him by tweet. Bossert worked in the Trump White House for 15 months, from the inauguration in 2017 to his resignation in April 2018. He is now an analyst for ABC News. He and other former aides tell Stephanopoulos Trump avoided Situation Room briefings – which his predecessor, Barack Obama, consumed – because, in Bossert’s words, “He didn’t like the idea that he had to go into it. He wanted everybody to come to him.” Bossert also says Trump had Situation Room aides produce “books of chyron prints” – a way to boil down cable news to the messages displayed at the bottom of screens. Stephanopoulos and Hickey call this “surely one of the most prosaic tasks ever required of the highly trained intelligence officers serving in the White House”. Though Bossert’s White House tasks including advising the president on cyber security, in August 2017 it was revealed that he gave his personal email address to a British prankster pretending to be Jared Kushner, Trump’s son-in-law and chief adviser. Still, Bossert was a strong advocate of cracking down on leaks and leakers. In March 2017, he made headlines by calling people who leaked government secrets “enemies to our state”, adding: “They need to be caught, punished, and treated as such.” Throughout his presidency, Trump fumed about leaks, both of sensitive information and regarding his chaotic White House. In summer 2020, as protesters for racial justice came close to White House grounds and Trump was reported to have been hurried to a protective bunker, Trump reportedly called those who leaked the story treasonous and said they should be executed. Trump was said to have become “obsessed” with finding leakers. But Trump has long been known to be a prolific leaker himself. Bossert tells Stephanopoulos: “I caught him doing it. I was walking out of the room, and he picks up the phone before I’m out of earshot and starts talking to a reporter about what just happened. And I turned around and pointed right at him. ‘Who in the hell are you talking to?’” Trump, the authors say, “essentially shrugged, seemingly unbothered”. “He does it, so he assumed everybody was that way,” Bossert says. “His paranoia was in part because he assumes everyone else acts like he acts.”