Turkey’s assault on the Kurds in the Afrin enclave in northern Syria complicates an already complex political and military situation. President Recep Tayyip Erdogan says the Syrian Kurds of the YPG are terrorists closely linked to Turkey’s own Kurdish rebels, the PKK, branded worldwide as a terrorist organization. The Afrin enclave, to the north of Aleppo, is controlled by the Syrian Democratic Forces (SDF) which comprise various parties opposed to the Assad dictatorship but are nevertheless dominated by the YPG.

The SDF has been backed by Washington, which has given money, arms and training. Until recently, Russia also had a military presence in the enclave. In the kaleidoscope of alliances, Moscow had itself given support to the YPG in its fight against Daesh (the self-proclaimed IS) on the basis that the YPG did not attack Damascus’ forces. Seemingly on the table was some vague idea that Assad would tolerate an autonomous Kurdish region in the northeast of the country.

For a long time, Turkey did little to stop the flow to Daesh of recruits, arms and money across its territory, apparently on the basis that the terrorists were assaulting its enemy, the Assad regime. An indirect result of that neglect, whether it was calculated or inadvertent, was to empower the YPG, which had itself been attacked by Daesh. The spectacle of the desperate struggle for the Kurdish-Syrian border town of Kobane in 2015 caused international outrage as substantial Turkish forces sat in their own territory on hills overlooking the besieged town and stopped any help being sent over the border to the hard-pressed Kurdish fighters of the YPG. When Ankara finally relented and allowed Kurds in Turkey to help in Kobane, the terrible battle against Daesh - which Turkey had vowed, publicly at least, to crush - was almost won.

But Kobane led directly to the Daesh suicide bombing of a Kurdish youth gathering in the Turkish border town of Suruc. The terrorist killed 33 and injured 105. A few days later two Turkish policemen were murdered in dubious circumstances. Ankara characterized the crime as a revenge attack for failures by the security authorities in Suruc. This was the point at which Erdogan tore up the 2013 peace deal he had cut with imprisoned PKK leader Abdullah Ocalan and restarted the war against Kurdish militants.

The Afrin incursion, like the attacks into Kurdish territory in Iraq, is an attempt by Erdogan to crush once and for all a PKK insurgency that began originally in 1984. Maybe the YPG’s apparent deal with Assad makes them a more legitimate target for Ankara. Meanwhile, Russian president Vladimir Putin, with whom Erdogan is now on very good terms, is pleased to see increased tensions between Ankara and Washington. The Americans are protesting the Turkish attack on their SDF surrogates. Turkish-US relations have not been at such a low ebb in 70 years.

But the Afrin incursion is fraught with risks for Erdogan. Generals will always tell their political masters that every military action they are ordered to undertake must have a clear objective and a feasible end. Turkish troops, however disciplined and well-equipped, do not face an easy struggle against battle-hardened YPG fighters. The end game is unclear. The only certainty is that Erdogan’s invasion is going to add to the myriad of uncertainties that already confront the region.