Here are 10 startling revelations from the new Trump tell-all book ‘A Very Stable Genius’
US President Donald Trump speaks about the impeachment inquiry during a tour of the Flextronics computer manufacturing facility in Austin, Texas (AFP Photo/MANDEL NGAN)

Thanks to a new book written by Washington Post national investigative reporter Carol Leonnig and White House bureau chief Philip Rucker, who are both Pulitzer Prize winners, we now have a clearer picture regarding some of the concerns around President Trump's mental and intellectual fitness for office -- a picture that was provided to White House reporter Ashley Parker for a book review published at The Washington Post this Wednesday. The book, A Very Stable Genius, is set to be released on January 21.

Below are some key takeaways from the book, as cited in Parker's book review:

Trump didn't seem to grasp the fundamental history surrounding the attack on Pearl Harbor

While taking a private tour of the USS Arizona Memorial in Honolulu, Hawaii, President Trump said to his then-Chief of Staff John F. Kelly, “Hey, John, what’s this all about? What’s this a tour of?”

“Trump had heard the phrase ‘Pearl Harbor’ and appeared to understand that he was visiting the scene of a historic battle, but he did not seem to know much else,” the book's authors wrote.

Early in his presidency, Trump could barely contain his eagerness to meet Russian president Vladimir Putin

According to the authors, during the transition Trump interrupted an interview with one of his secretary of state candidates and asked, “When can I meet Putin? Can I meet with him before the inaugural ceremony?”

After meeting Putin for the first time, Trump immediately declared himself to be a Russia expert and dismissed the expertise of then-Secretary of State Rex Tillerson

"Tillerson’s years of negotiating with Putin and studying his moves on the chessboard were suddenly irrelevant," the authors wrote. "'I have had a two-hour meeting with Putin,’ Trump told Tillerson. 'That’s all I need to know. . . . I’ve sized it all up. I’ve got it.'"

Trump clashed with Tillerson after trying to task him with getting rid of the Foreign Corrupt Practices Act, which prevents U.S. firms and individuals from bribing foreign officials for business deals

“It’s just so unfair that American companies aren’t allowed to pay bribes to get business overseas,” Trump says, according to the book's authors. “We’re going to change that.”

Speaking to the authors, a government aide accused Trump of destroying the "gravity and allure" that surrounds the presidency

"He’s ruined that magic,’ this aide said. "The disdain he shows for our country’s foundation and its principles. The disregard he has for right and wrong. Your fist clenches. Your teeth grate."

Then-Deputy Attorney General Rod J. Rosenstein and other senior officials ran through private "fire drills" in case Trump triggered a “Saturday night massacre” -- a reference to the mass resignations under President Nixon during the Watergate scandal

“They prepared for several scenarios: If Trump fired [then-Attorney General Jeff] Sessions, if Trump fired Rosenstein, and if Trump ordered the firing of Mueller,” the authors write.

While participating in an HBO documentary, Trump attempted to read aloud from the Constitution, but had a hard time reading the text

“It’s like a foreign language," Trump reportedly said.

Trump, who rails against people who leak details to the press, is a leaker himself 

After turning down Trump's offer to be his chief of staff, former New Jersey governor Chris Christie asked Trump how the details of their meeting leaked out.

“Oh, I did it,” Trump replied.

Trump was “verbally and emotionally abusive” toward then-Homeland Security Secretary Kirstjen Nielsen

According to the book, "He made fun of her stature and believed that at about five feet four inches she was not physically intimidating. 'She’s so short,' Trump would tell others about Nielsen. She and Kelly would try to make light of it. Kelly would rib her and say, 'But you’ve got those little fists of fury!'"

When former White House staff secretary Rob Porter was fired as a result of allegations of domestic abuse from his two ex-wives, Trump offered an excuse for him after a photo surfaced of one of Porter's ex-wives with a black eye 

“Maybe, Trump said, Holderness purposefully ran into a refrigerator to give herself bruises and try to get money out of Porter?” the authors wrote.

You can read Parker's full book review over at The Washington Post.