Vladimir Putin’s announcement that Russia would start pulling out “the main part” of its military forces from Syria has startled the world. Even the US administration was apparently left struggling to make sense of Russia’s about-turn, just six months after it rattled western policymakers by launching its military intervention. It looked, yet again, as if Washington had been caught out by Russia’s president in a crisis which has repeatedly tested US credibility. But the deeper question is what lies behind Mr Putin’s move, and how it may affect events.

Speculation inevitably plays a part in assessing the impact of Russia’s sudden move in a war that has caused over 300,000 deaths and of which, despite the recent two-week lull in fighting, there is as yet no end in sight. One hope among western diplomats is that Mr Putin will drop President Bashar-al-Assad, now that he has demonstrated Russian power in the Middle East. This would go a long way in forwarding peace talks, because Mr Assad’s fate has been such a stumbling block. But many signs point the other way. Russian intervention has consolidated and entrenched Mr Assad, and has put an end to the military setbacks suffered by the Syrian regime in 2015. So Russia can now capitalise on that by appearing to step back. It has already done enough to take the upper hand on what may lie ahead for Syria.

It was no coincidence that Mr Putin made his announcement as diplomatic talks were due to restart in Geneva. This allows Russia to appear dedicated to ending the war by becoming the first to start pulling forces out of Syria, rather that putting more in. It is precisely because perceptions have too often counted for more than realities that this appearance should be treated with caution.

Russia’s Su-34 fighter planes flew out of the warzone on Tuesday in a blaze of publicity. But it remains to be seen how consistent and wide-ranging this pull-back will be. Reports of Russian air raids continued on Tuesday. And Russia has made clear it will keep the military installations it has built up on Syria’s coast. This means it can restart air operations whenever it chooses to. In that respect, Mr Putin has kept his options wide open.

Mr Putin can also say Russia has largely fulfilled its objectives. He has achieved two main things: he has prevented Mr Assad’s defeat, and he has made it impossible for the US and its European and Turkish allies to create safe zones in Syria which, in other circumstances, might also have offered a strong platform for the anti-Assad rebel forces the west has tried to support. Those rebels have been the main targets of Russia’s intervention, especially in Aleppo. Now that Russia has deployed its S-400 air defence systems in Syria, direct western intervention in the civil war is now militarily as well as politically inconceivable. Mr Putin is a master of diplomatic ambiguity. He says Russia’s partial withdrawal can help facilitate a negotiated settlement. And the Kremlin has drawn attention to a phone call Mr Putin made to Mr Assad, in which the Syrian president supposedly committed to a political settlement. Russian pressure may indeed now be piling up on Mr Assad, who claimed recently his forces would retake the whole country, and Mr Putin no doubt wants to avoid getting sucked irrevocably into Syria. But whether this means Mr Assad will eventually step aside, or even whether Russia wants his removal, is a different matter.

In both Syria and Ukraine Mr Putin wants to cast Russia as a power that cannot be ignored. He believes – not without good evidence – that he can win credit with Russian public opinion whenever he appears to outfox the US. At a time of great financial constraints for Russia, with global oil prices down and sanctions biting, that matters. Russia’s state media is already celebrating a victory in Syria, showing pilots acclaimed by crowds, as bands play the national anthem.

If there is one thing that Mr Putin’s announcement makes plain, it is that Russia’s claim that it was moving into Syria to combat Islamic State has been exposed as a sham. Not only has Isis been spared most of Russia’s air attacks, but it has arguably benefitted from the setbacks that Russia has inflicted on Syrian rebel forces. Isis has not been crushed. Instead it has been able to move forward, especially round Aleppo. That does not seem to matter to Mr Putin, whose geopolitical goals lie elsewhere. Yet Russia has caused hundreds of extra civilian deaths and may have strengthened Isis. Mr Putin likes to give the impression he knows what he is doing in Syria. But his record there may prove truly dire and destructive.