Yesterday, Recep Erdogan threatened to attack the YPG, the Syrian Kurd force that on which the US will rely for the advance on the ISIS stronghold of Raqqa. Today, they’re humming a somewhat different tune. The Financial Times interviewed Turkey’s prime minister, who now credits Defense Secretary James Mattis for explaining what should have been obvious all along, and  who sounded the retreat:

[I]n an interview with the Financial Times, Binali Yildirim, prime minister, indicated that Turkey had been reassured by James Mattis, US defence secretary, whom he met in London on Thursday.

“Turkey’s concerns are understood but on the ground this was a tactical alliance and they had no choice,” said Mr Yildirim, referring to the US argument that the Syrian Kurds — which Turkey regards as a terrorist group on its border — will be vital in the battle to capture Isis’s northern Syria heartland of Raqqa.

“The defence secretary on numerous occasions made very, very clear, an unequivocal commitment that they would never allow those weapons to be turned against Turkey,” he added.

Why the switch? Part of it might have been being told it was already a fait accompli:

“We believe that those heavy weapons were already on the ground in Syria, but they needed a mandate to use those weapons during the siege of Raqqa,” he said. The US has long seen the Syrian Kurds as the most effective fighting force against Isis in the country.

Part of this fallback position could be a recognition that US patience with Erdogan might also be running thin, too. Jazz noted a number of issues that raise questions about why Trump’s receiving Erdogan at the White House at all, let alone after publicly threatening to attack our Kurdish allies just as they’re about ready to step off against ISIS in Raqqa. Erdogan is making himself a lot less indispensable these days, and giving NATO some reasons to rethink their partnership with Turkey. They don’t want Russia to co-opt it, but Erdogan seems to be leaning in that direction anyway.

That’s what makes this backpedal so transparent. Of course that’s a tactical alliance; no one in the US government has ever indicated otherwise. It’s either the YPG and the larger contingent of the Syrian Democratic Forces (of which they are the largest number), or American troops that will have to conduct a large-scale urban assault on a heavily defended city. As much as Trump might like to take sole credit for a victory there, he knows he’ll never get enough support to throw tens of thousands of troops into Syria, not even to crush ISIS.  It appears as though Erdogan might have wanted to test Trump to see if he’d back away from the YPG, and didn’t get the answer he hoped.

Just how soon will this alliance start taking action? It might be as soon as next month, according to al-Jazeera:

The Syrian Democratic Forces (SDF), a US-backed group, says it will soon begin a final attack to capture Raqqa, ISIL’s self-proclaimed capital in northern Syria, just days after seizing a key town to the west and an adjacent dam. …

SDF commander Abdul Qader Hevdeli said on Friday the push to Raqqa “will be in the coming period of time.

“I can’t specify exactly; I believe entering and storming the city will happen at the start of the summer,” he said in a news conference in Tabqa city, which the SDF took from ISIL on Wednesday.

Hevdeli said the US arms shipments would “arrive soon” and added that Raqqa would be captured without help from other forces.

If that’s true, then Erdogan will find out shortly just how committed we are to retrieving our heavy materiel.