After my recent trip to Syria, I knew Afrin's fall was inevitable – now we must concern ourselves with the next phase of war

The fall of Afrin city to the Turkish army and Syrian rebel forces was inevitable, but the situation remains full of dangers. A central question now is whether or not the takeover of this Kurdish enclave will lead to the ethnic cleansing of the Kurdish majority there.

The first act of the fighters of the Free Syrian Army (FSA) fighters, an overwhelmingly Arab force, was to bulldoze the statue of a Kurdish mythological hero in the centre of Afrin. Videos taken by FSA fighters suggest that many are former Isis or al-Qaeda fighters who see the Kurds and non-Muslim minorities as enemies to be expelled or eradicated.

Some 200,000 Kurds have fled from Afrin over the past few days, many suspecting that they will never be permitted to return. If they are right, they will join the six million Syrians displaced since 2011 and a similar number who have become refugees outside the country. Given that the Syrian population in that year was about 23 million people, more than half have lost their homes in seven years of violence.

Afrin was easy pickings for Turkey: it is on the Turkish border and cut off from the main body of Kurdish-held territory east of the Euphrates. The only supply route south to Aleppo was controlled by the Syrian army, which would allow civilians to pass but not arms and ammunition. YPG commanders said that they had 10,000 men in the enclave, but there was never much sign of their presence. The FSA says it was able to enter the city without resistance from three directions on Sunday morning, though another report claims that some fighting is still going on.

The commanders of the Kurdish People’s Protection Units (YPG) were evidently convinced that Afrin was indefensible and pulled out because they had no alternative. If this was the case, then they were wise not to fight to the finish in a battle they were bound to lose with heavy loss of life.

The outcome of the struggle for Afrin was evident from the moment the Turkish invasion began on 20 January. The occasion of it was a provocative statement by the then US Secretary of State Rex Tillerson that US forces were going to stay in Syria, thereby guaranteeing the security of the de facto Kurdish state created by the YPG-US military alliance against Isis. By the time Isis was defeated when Raqqa fell last October, the Kurds had gained control of about a quarter of Syrian territory.

Tillerson declared that the US would not only stay in Syria – something it had promised Turkey would not happen once the battle against Isis was won – but would also seek the departure of President Bashar al-Assad from power and the rolling back of Iranian influence. These were ambitious and unrealistic aims, but they were enough to bring Turkey and Russia together.

President Putin withdrew the Russian air umbrella protecting Afrin, enabling the Turkish air force to bomb at will. This was decisive: the YPG are determined and experienced soldiers but they have no air defence or heavy weapons and knew they could not win.

Russia presumably wants to lock the Turks into a permanent conflict with the US as the allies of the Kurds. It will also make Turkey somewhat dependent on Russia since its forces will be carrying out military operations in an area in which Russia is the superior power.

What happens next after the fall of Afrin? The first thing to see is whether it is followed by ethnic cleansing and the “Arabisation” of the enclave. The removal of opposing ethnic or sectarian communities has become a frequent feature of the Syrian civil war.

For the Turks this may have been an easy victory, but it is still a victory. It will make them a more important player in the Syrian crisis, but they could overplay their hand.

President Recep Tayyip Erdogan is triumphant, maybe too triumphant. He said on Sunday that “in the centre of Afrin, symbols of trust and stability are waving instead of rags of terrorists”. Destruction of Kurdish symbols in the city is not a good sign for the future. Some Syrian Kurdish leaders fear that Erdogan plans to create a Sunni Arab bloc under Turkish control in northern Syria.

A crucial question is where Erdogan goes from here. He may have got Afrin, but the main Syrian Kurdish zone stretches from the Arab city of Manbij, just west of the Euphrates to the Iraqi border, is still where it was. Here, unlike Afrin, the Kurdish and Kurdish-linked forces are under US protection. Very visible patrols of US armoured vehicles patrol the front line around Manbij. It will also be easier for the YPG to fight close to their main territorial bases.

The Kurds fear the US might abandon them, but purely from the point of view of US interests, the US needs an allied ground force in Syria if it is to remain a power there and the only candidates are the Kurds. “If the US abandons the Kurds, then it will have to leave Syria,” said one Kurdish leader. US commitment may ebb, but it has not happened yet. If Erdogan wants to move against the main Kurdish enclave in Syria, he will have to bide his time.