The book, Fear, shares stories about top officials worried that the president’s erratic behavior would threaten national security. Gary Cohn, the president’s former top economic adviser, went so far as to steal a letter from Trump’s desk about NAFTA to prevent him from signing it and ending a vital trade agreement, The Washington Post reports.

In another instance, Defense Secretary James Mattis allegedly said Trump had the comprehension of “a fifth- or sixth-grader” after having to explain to the president that the U.S. military presence on the Korean peninsula is intended “to prevent World War III”—just one instance when aides had to explain governing basics to the president.

In another, Trump allegedly wanted to assassinate Syrian leader Bashar al-Assad following the dictator’s civilian chemical attack last year. Mattis reportedly told the president he’d follow the orders, but then told aides, “We’re not going to do any of that. We’re going to be much more measured.”

“He’s an idiot,” Chief of Staff John Kelly said about the president another time, Woodward writes. “It’s pointless to try to convince him of anything. He’s gone off the rails. We’re in Crazytown. I don’t even know why any of us are here. This is the worst job I’ve ever had.”

Trump, meanwhile, allegedly told Commerce Secretary Wilbur Ross, “I don’t trust you. I don’t want you doing any more negotiations. … You’re past your prime.” He also reportedly called Attorney General Jeff Sessions “mentally retarded,” and said former national security adviser H.R. McMaster dressed “like a beer salesman.”

The stories continue, adding to a growing library of books describing chaos at 1600 Pennsylvania Ave. According to CBS News, Fear is set to be released later this month.

While books about the Trump administration are nothing new, The Atlantic suggests Woodward’s book will be more influential than the others. Woodward has his critics, but based on his well-regarded reporting during the Watergate scandal, Woodward is expected to avoid some of the problems of Michael Wolff’s Fire and Fury, which was published in January of this year. Woodward also can’t be targeted with claims of being a disgruntled ex-employee, like Omarosa Manigault Newman, who wrote Unhinged, published just last month.

Woodward, an associate editor at The Washington Post, gathered material for his book through government documents, meeting notes, personal diaries, and hundreds of hours of interviews (although some interviews had to be reported anonymously, The Post writes). He tried several times to reach the president himself for an interview, according to the Post, but was not successful.

Trump then reached out to Woodward after the manuscript was completed, belatedly saying he wanted to participate.