President Trump warned his Turkish counterpart in a letter that the world would “look upon you forever as the devil” if he didn’t find a peaceful resolution to tensions with Syria, it was revealed Wednesday.

“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,” wrote Trump in the letter to President Recep Tayyip Erdogan, confirmed as authentic by the White House. “Don’t be a tough guy. Don’t be a fool!”

The missive is dated Oct. 9, the day that Turkish troops began their foray into northern Syria against the Kurds — longtime US allies condemned as alleged terrorists by the Turks.

“Let’s work out a good deal!” the letter begins. “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.”

Trump made good on that vow on Monday, hitting Turkish officials with sanctions, doubling steel tariffs against the nation and pausing a $100 billion trade deal.

“I have worked hard to solve some of your problems,” continued Trump. “Don’t let the world down. You can make a great deal.”

Trump also tried to play peacemaker between Erdogan and Kurdish General Mazloum Kobani of the Syrian Democratic Forces.

“General Mazloum is willing to negotiate with you, and he is willing to make concessions that they would never have made in the past,” wrote Trump. “I am confidentially enclosing a copy of his letter to me, just received.”

Trump signs off the letter by writing, “I will call you later.”

Shortly before the invasion began, Trump reduced the number of American troops in northern Syria to pave the way for the Turkish incursion, a move that has received fierce bipartisan criticism in the US.