Vladimir Putin is full of surprises. His decision to withdraw Russia’s “basic forces” from Syria was forecast by no one. The Russian president’s courtiers will presumably be keeping him abreast of the many interpretations of his latest Syria gambit, no doubt emphasising the sagacity and success of his bold intervention in the region. So what does the balance sheet look like? And, in so far as it is possible to discern the motives of this most mercurial of leaders, what are they?

When the Russian air force entered Syrian airspace last September, three of the president’s aims seemed clear. The first was to salvage the crumbling regime of Bashar al-Assad. The second was to re-establish Russia as an important actor in the Middle East. Mr Putin, who mocks the US and Europe for the fiascos of their regime-changing adventures from Iraq to Libya, also clearly intended to teach the west a lesson — and so relieve western pressure resulting from his own intervention in Ukraine. The lesson turned out to be a Russian remake of “shock and awe”.

From the outset Russian warplanes struck at Sunni rebels threatening Damascus and Mr Assad’s coastal enclave in north-west Syria, rather than at Isis jihadis — a declared target of the operation. He used peace negotiations jointly chaired with the US in Geneva as a smokescreen behind which to lay waste to any middle ground between the Assad regime and Isis. This showed up the west as too feckless to help Sunni rebels whom the US and regional allies such as Saudi Arabia and Turkey had backed against the Assads.