What did Donald Trump do today?

He got his bluff called by Turkey in a humiliating fashion.

On Sunday, Trump announced—without having consulted anyone in the State Department or the military—that he was withdrawing American troops from their protective role in Syria. The effect was to abandon the United States' allies in the Syrian conflict, the Kurdish-led Syrian Democratic Forces. There was bipartisan outrage over the move.

On Monday, in an attempt to ease fears that the authoritarian government of Turkey (which is hostile to the Kurds) would attack the SDF, Trump tweeted a threat to "totally destroy and obliterate the Economy of Turkey" if they did "anything that I, in my great and unmatched wisdom, consider to be off limits." Turkey's vice-president responded that the country would "not react to threats."

This afternoon, in an attempt to undo the damage of the previous two days and demonstrate some control over the situation, Trump announced that he would welcome Turkish president Recep Tayyip Erdoğan to the White House in November. 

Tonight, reports are coming in that Turkey is shelling SDF forces and that a ground invasion is imminent, in coordination with Russia. The SDF has announced that guarding prisons containing captured Islamic State prisoners is now a "second priority" because of the Turkish threat.

Trump profits from the licensing of his personal brand on property in Turkey* and admitted during the campaign that he has a "conflict of interest"—his words—where that country is concerned. Trump's election was accomplished with help from Russia, as a Republican-led Senate panel confirmed today.

Why does this matter?

• Countries that abandon their allies end up without allies.

• Anyone who puts their personal or political needs above those of the country is unfit to be president.

• Being disregarded like this makes Trump, and the United States, look incredibly weak.

* Trump licenses his name to Trump Towers Istanbul, but does not own them. A previous version of this post mistakenly identified him as a property owner in Turkey.