A woman holds the PKK (Kurdistan Workers' Party) flag during a demonstration against Turkish President Tayyip Erdoğan in 2016.Yves Herman / Reuters

The great virtue of Twitter is that it forces users to be concise. One downside is that when an extremely powerful crazy person—the president of the United States, say—uses it, he can sound a bit like the Abrahamic God in one of his more wrathful moments. “If Turkey does anything that I, in my great and unmatched wisdom, consider to be off limits, I will totally destroy and obliterate the Economy of Turkey (I’ve done before!),” Trump thundered today, as House Republicans scrambled to burn offerings in the Rotunda.

The subject of this tweet, Turkey, had just hours before been the unconditional beneficiary of a sickening desertion by the United States. Late last night, the White House issued a statement confirming that the United States would stand by while Turkey asserted control over northern Syria—including territory controlled by the Kurds, who have been integral to the anti–Islamic State coalition. The Kurds were an American ally, but not a natural one: The PKK (Kurdistan Workers’ Party), which runs Kurdish affairs in Syria, fought against Turkey in the 1980s and ’90s and remains cultish in its Maoism. (Whatever Fox News viewers think Representatives Alexandria Ocasio-Cortez and Ilhan Omar believe, the PKK actually believes.) Turkey has consistently promised to strangle any Kurdish state before it becomes permanent. Apparently Trump assented to the Turkish position, and in a hurry to extricate America from northern Syria, abandoned the Kurds to the mercies of their most powerful enemy.

Geopolitics is a contest of bad ideas, with winning defined as implementing the least-bad ones. Letting Turkey take control of Kurdish territory falls somewhere between “very bad” and “extremely bad” in this range; the only question is whether the alternatives fell into the rarely visited “shockingly, horrendously bad” portion of the spectrum. To leave the Kurds to Turkey amounts, first of all, to the total betrayal of an American ally, a group whose members have died in the desert by the thousands, so that we Americans didn’t have to revisit our bad dreams of the Iraq War by fighting in large numbers. The Kurds had their own reasons to despise the Islamic State—their ideology is Marxist and atheist, and ISIS would have slaughtered them all—but anyone who prefers Arlington National Cemetery to remain uncrowded owes thanks to the Kurds who died in our soldiers’ place. Letting our allies get annihilated is a fast way to ensure that we never have allies again.

Trump’s advisers (but who can advise Yahweh?) seem to understand this: His Defense Secretary James Mattis resigned in part because he refused to sell American allies downriver; and Eliphaz the Temanite, I mean Senator Lindsey Graham, spoke up this morning to say that if Turkey attacks the Kurds, he will try to sanction it and get it suspended from NATO. The advice seems to have elicited Trump’s threat to “obliterate” Turkey’s economy, and the mysterious, false claim that he had done so before. The complication here, however, is that Trump has saved an American ally (the Kurds) by pledging to devastate, according to his awesome whimsy, another American ally. It may seem odd to refer to Turkey—an autocracy with a theocratic touch—as an ally, but it is literally an ally, in the formal sense that it belongs to NATO, and is therefore in a very elite club, with obligations of mutual defense and neoliberal omertà that the Kurds lack. It is neither simple nor wise to treat that relationship recklessly.

Nor is it possible to implement a foreign policy in Syria without some Turkish cooperation. Recall that when the Islamic State seized Mosul, Turkey had to negotiate for the lives of the dozens of Turkish diplomats kidnapped from its consulate. The terms of that negotiation remain unknown, but we do know that in the next year or so, Turkey and the Islamic State somehow avoided major confrontation, almost as if they had a time-limited armistice. During that time the fight against the Islamic State stalled.

Allies and potential allies will watch this farce of geopolitics and again wonder what an alliance with America is really worth, if it can be flushed away one night and restored the next—or if there’s always the part where Trump says something, then the part where he takes it back. Trump’s signature trait as a real-estate mogul was that a Trump deal was never, ever a deal. His word meant nothing, and if you thought it did, he’d snatch up your money and walk away with it. As president he is no different, and by this afternoon there is not one ally but two who have been reminded never to trust him—to extend him no credit, to assume he’ll reserve the right to rewrite, unilaterally, the terms of your agreement, and force you to accept his new terms. The old diplomatic wisdom was that you should reward your friends and punish your enemies. To act completely undependable, both as an enemy and as an ally, serves no obvious purpose.

Many bad decisions are made in moments of frustration, and the acute reasons for the White House’s frustration are clear from last night’s statement. It remarked on the continued failure of “France, Germany, and other European nations” to repatriate and prosecute their citizens who joined the Islamic State and are now imprisoned by the Kurds. “Turkey will now be responsible for all ISIS fighters in the area,” according to the statement. They include some inmates of al-Hawl refugee camp, swollen with about 70,000 inhabitants. The administration’s anger is wholly justified: Wild-eyed, murderous Frenchmen and Germans are in that camp, and the countries whose passports they carried owe the rest of us (most of all the Syrians and Iraqis whose territory they terrorized) an attempt to prosecute them. Instead the ISIS fighters and sympathizers are kenneled together with victims and, according to all reports, are still killing people and plotting from within the camp. Eventually the people in it will rebel, break out, and get the old jihadist bands back together—maybe in Syria, maybe in Europe, maybe somewhere else.

Unfortunately, to declare with a booming voice from the heavens that Turkey is now in charge does not solve the problem at all. Indeed, the Kurds now know that their efforts to secure the foreign fighters is getting them little respect from the United States or anyone else, and they’re likely to divert their resources away from detainment of terrorists and toward the more pressing matter of not being invaded and killed by Turkey.

The White House’s very brief statement twice mentioned that the United States had finished off the Islamic State’s “territorial ‘Caliphate.’” The triumphal tone is unmistakable: We won, and now we get to go home and leave the Turks to clean up the mess. But we never really won, because the territorial caliphate never constituted more than a part of the mess—and the solution to the mess created, as most political solutions do, a mess of its own. The Syrian war is not over, and leaving it behind won’t make it stop, though abandonment will limit our say over how it continues, and who gets killed or terrorized along the way.

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