What did Donald Trump do today?

He suggested that Syrian Kurds ethnically cleanse themselves.

Trump today tweeted that the United States' Kurdish former allies against the Assad regime and ISIS should leave the parts of Syria they have lived in for centuries and "start heading towards the Oil Region."

By definition, this would be ethnic cleansing.

Since the White House didn't—and presumably couldn't—explain exactly what this meant, it's a little unclear what Trump thought he was saying. But the "Oil Region" of Syria is hundreds of miles away from the areas that Kurds are being forced to flee by advancing Turkish forces and Turkey-allied militias. 

There is no reason to think that literally millions of Kurdish refugees would be welcome in the Arab-dominated oil-producing regions of Syria, or that the region could support such a huge population influx, or that the several hundred American troops Trump plans to leave in the region could do anything to protect them.

Trump, who can hardly afford yet another foreign policy debacle, seems desperate to claim some kind of victory after inexplicably giving Turkey the go-ahead to invade northern Syria and launch attacks on the Kurdish population in the region. 

In the same tweet, Trump said he "really enjoyed" speaking with Mazloum Abdi, the leader of the Kurdish troops in the region, and that Abdi—again, according to Trump—"appreciates what we have done." In reality, Abdi has expressed horror at what the Kurds (and much of the rest of the world, and an overwhelming bipartisan majority in Congress) see as a betrayal.

Why is this a bad thing?

• Ethnic cleansing is a crime against humanity.