Trump's Letter to Turkey's Erdogan Shows President is 'Deeply Unwell,' Says Historian: 'So Threatening, So Unhinged, So Bizarre'

A letter by President Donald Trump urging the Turkish leader Recep Tayyip Erdogan not to "be a tough guy" over his bombardments in northern Syria, breaches all standards of diplomacy and etiquette and shows that the U.S. president is mentally unwell, a political historian has said.

The letter dated October 9 was initially obtained by a reporter from Fox Business and confirmed by the White House as authentic.

In it, Trump says he would wreck the Turkish economy if Erdogan went too far with his invasion which followed the U.S. president's sudden withdrawal of U.S. troops from the region.

The letter read: "You don't want to be responsible for slaughtering thousands of people, and I don't want to be responsible for destroying the Turkish economy—and I will.

"History will look upon you favorably if you get this done the right and humane way. It will look upon you forever as the devil if good things don't happen."

"Don't be a tough guy. Don't be a fool!" he added.

News networks expressed bewilderment at the letter, whose date suggests that it was ignored by Erdogan, who proceeded with his attacks on northern Syria.

Among those on Twitter voicing their bemusement, was U.S. foreign relations expert Brad Simpson, an associate professor at the University of Connecticut.

In a thread he tweeted to his 14,000 followers, Simpson said: "I am a historian of U.S. foreign policy. I have read many, many letters from U.S. Presidents to foreign leaders, and I have never read a letter from the U.S. President so unhinged, so threatening, so bizarre, so completely lacking in basic etiquette. Trump is deeply, deeply unwell."

Simpson concluded that Trump had dictated the letter straight to a secretary without any input from top state department, or Pentagon advisers and that, "it's hard to overstate how crazy this is, given the stakes involved for U.S. in Turkey's invasion of Syria."

He said: "This letter suggests a complete breakdown of the policy-making process and a President who is totally improvising with no input from advisors, since no competent, serious policymaker would ever sign off on such a letter. It just would not happen."

Simpson's view was echoed by many on social and mainstream media. Democratic congressman Mike Quigley told CNN: "I actually thought it was a prank, a joke, that it couldn't possibly come from the Oval Office."

"For him to write this and to also say that it doesn't affect us is ignorance at the highest level," he added.

Michigan Rep. Justin Amash curtly tweeted: "This is insane," while Rep. Seth Moulton of Massachusetts told Business Insider: "An average student at one of America's failing high schools could write a more effective letter than this."

Meanwhile, house speaker Nancy Pelosi and other Democrats walked out of a White House briefing with Trump over the U.S. troop withdrawal after she said the president started insulting her.

Pelosi said: "I pray for the president all the time ... I think now we have to pray for his health—this was a very serious meltdown on the part of the president." Speaker Pelosi started trending in the U.S. after she made as her Twitter cover image, a photo of her meeting with Trump that the president had tweeted out, calling it "Nervous Nancy's unhinged meltdown!"

On Wednesday, 129 House Republicans crossed party lines and voted to rebuke Trump's decision to withdraw U.S. troops.