The record of Turkish involvement in the war in Syria over the last five years has been one of repeated disaster. It wanted to get rid of President Bashar al-Assad and his government and it is still there and in control of at least two thirds of the Syrian population. Instead, the Syrian wing of Kurdistan Workers’ Party (PKK), which has been fighting a guerilla war against the Turkish state since 1984, was able to establish its rule, with the military backing of the US, across a great swathe of northern Syria south of the border with Turkey. Isis, which Ankara once tolerated, has launched a vicious bombing campaign in Turkey which killed 54 people at a wedding in Gaziantep last weekend.

Will Turkey's military incursion, which began at 4am this morning, fare any better than its past initiatives in Syria? Its tanks, special forces amd artillery are backing at least 500 Syrian rebels in an attack on the Isis-held town of Jarabulus just west of the Euphrates River. The Turkish media speaks of the operation, known as “Euphrates Shield”, as aiming to create a 55-by-25 mile “safe zone” for refugees just south of the Syrian-Turkish border. But Turkish Deputy Prime Minister Numun Kurtulmus says that what we are seeing is “a short and results based operation”. Opposition forces said this evening that they were in control of the town, as US military officials said that American planes were conducting air strikes against Isis targets.

One aim is to respond to the massacre carried out by an Isis suicide bomber in Gaziantep last weekend. Another is to prevent the Syrian Kurds, the shape of its proxy, the Syrian Democratic Forces (SDF), taking Jarabulus and the 30-mile strip to its west, which is Isis's last exit and entry point to Turkey and the outside world. This would extend the Syrian Kurdish quasi-state, which the Kurds call Rojava, connecting up to the Kurdish enclave of Afrin north-west of Aleppo. Going by the limited number of tanks and other forces so far committed by Turkey, its ambitions in Syria are at present fairly limited.