Art of the Deal ghostwriter explains terrifying reason Trump is attacking allies: ‘He’s mentally ill’
Tony Schartz co-authored "The Art of the Deal" with Donald Trump

Tony Schwartz, the ghostwriter who actually wrote "The Art of the Deal," said that President Donald Trump's wild attacks on longtime American allies will likely only grow worse.

Schwartz began by saying Trump's behavior is entirely consistent with how he's behaved in the past when he's let his ego destroy personal relationships with others.

"His interest is almost entirely about how he is seen or how he thinks he's seen," Schwartz explained. "And therefore his perspective is a very... it's wearing blinders. All he cares about right now, particularly in light of what happened at the G7, is that he can restore in his own mind his sense of self. And what's so fragile in Trump is his sense of self."

Schwartz went on to say that Trump instinctively lashes out at any criticism and simply will not tolerate listening to anyone tell him he's wrong about something.

"I'm going to say it very bluntly: He's mentally ill," he said. "This is a man -- and I understand I'm not a psychiatrist, but he's prima facie mentally ill. He has a personality disorder. That means on its face this is a man who is unstable, who doesn't think clearly and has narrowed his frame by pushing out anybody who will disagree with him."

CNN's Alisyn Camerota interjected to point out that many White House aides come on her show to insist that Trump is in possession of all his faculties.

"Alisyn, I love you, but that's nonsense," Schwartz replied.

Watch the video below.