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.