Turkey’s incursion into northern Syria has displaced tens of thousands of civilians, most of them Syrian Kurds. As with the Turkish army’s forays into Jarabulus in August 2016 and Afrin in March 2018, its reliance on Syrian Arab militias for the assault has not lessened the impression of vengeful marauding. (Many of the militias were once supported by the United States and Britain in their abortive attempt to bring down Bashar al-Assad.) As before, there are multiple accusations of war crimes. The difference this time is that the incursion and its consequences for the Syrian Kurds have clearly been tacitly authorised by the United States.

The US used the Syrian arm of the Kurdistan Workers’ Party (PKK) in the fight against Islamic State, and gave the impression it would provide protection for an autonomous Kurdish statelet in return. But once IS was defeated, the US always planned to leave the Kurds to fend for themselves.

The faction of DC analysts that wanted an indefinite US deployment in Syria are professing outrage; they see the debacle as evidence that Trump is allowing a decline in American influence and prestige. But the US retreat was if anything overdue. Washington came to terms with the continuance of Assad’s rule under Obama. Robert Ford, a former US ambassador to Syria, predicted a withdrawal in November 2017. Trump threatened to pull US forces out last December, but was talked down at the last minute by advisers who warned that IS may return. That fear remains but with IS militarily defeated a withdrawal was inevitable.

The Kurds must have suspected that the US never intended to stay the course. (Is it betrayal if you know from the beginning that deception is guaranteed?) On 16 October, the US marked its departure in dramatic fashion when it blew up its base at the Lafarge cement complex south of Kobane. In this context, Trump’s absurd letter to Erdogan, the temporary US sanctions on Turkey, Mike Pence’s visit to Ankara and the paper-thin ‘ceasefire deal’ counted for little: an off-key flourish from a departing band.

Whatever horrors are currently unfolding in northern Syria, they are unlikely to match the massacres and destruction the Turkish army wreaked in 2015 and 2016 when it tried to crush the PKK in Turkey’s own Kurdish provinces. At least 4000 people were killed. The historic centre of Diyarbakir was gutted. The entire city of Sirnak was levelled. In Cizre, the Turkish army slaughtered 178 people who had taken shelter in the basements of three blocks of flats. Those crimes have already been largely forgotten.

Turkey’s ability to impose its ugly designs on the predominantly Kurdish borderlands is limited. The dominant foreign power in Syria is Russia, and Putin and Assad have their own ideas about the future of the Syria-Turkey border. Erdoğan travels to Sochi tomorrow for talks. The most likely outcome is a negotiated return of Russian and Syrian government forces to the border. They have already taken control of the Kobane crossing.

The Rojava project, a quasi state of confederated communes operating under the noses of the Turkish, Syrian and Iraqi governments, was always a fragile undertaking. The chaos of the civil war and the enticements of the US gave the PKK the impression it could fulfil its aspirations. Syria’s Kurds may have hoped for a longer period of US protection to establish a defensible polity. Now they must press their claim with Damascus and Moscow.