When Vladimir Putin went to the rescue of the embattled Syrian president Bashar al-Assad and ordered Russian air strikes on Syria last autumn, defence officials in Moscow said the bombing campaign was time limited, but were vague about how long it might last.
Five months later the war in Syria has become more vicious and complicated and is threatening to escalate into a broader regional conflict drawing in Nato-member Turkey, Saudi Arabia and Qatar.
Western powers are pushing for implementation of a selective cessation of hostilities agreed in Munich last week, and on Monday the United States and Russia agreed on the terms of such a truce to take effect from this weekend.
But a full ceasefire can’t happen without Kremlin co-operation and Putin is not in a hurry to ground his war planes.
As Russia continued the bombardment of Aleppo in northern Syria, Britain's foreign secretary Philip Hammond was wondering what Putin was about. "The point about dealing with Russia is that they are not transparent," he told CNN.
“We don’t have good visibility about their intentions or whether they have the appetite for a longer engagement [in Syria].
"As the Kremlin's strongest ally in the Arab world, the Syrian regime is an anchor for Russian power in the Middle East. Syria holds the key to Tartus port, Russia's only naval base on the Mediterranean and a vital outlet for Russia's growing arms sales.
And its location bordering Turkey, Jordan, Lebanon, Israel and Iraq provides a foothold in the Middle East that is too important for the Kremlin to lose.
Putin's intervention in Syria, like his invasion of Georgia in 2008 and the annexation of Ukraine's Crimea in 2014, was a reckless gamble.
But from a military perspective it has so far delivered success. While US air attacks launched a year earlier have brought some setbacks for Islamic State, they have failed to change the strategic reality on the ground.
In contrast Russia, with a single air squadron flying hundreds of sorties a day, has shifted the conflict decisively in Assad’s favour, allowing government troops to drive opposition rebels out of the Syrian president’s strongholds in the east and press north towards the Turkish frontier and the strategic city of Aleppo.
For ordinary Russians the air strikes have been a remarkable show of power, distracting from the unfinished conflict in eastern Ukraine and the grinding dreariness of life under the "new reality" – Kremlin propagandists' code for economic crisis.
Instead of distressing images from eastern Ukraine, state television has footage to show of the Russian air force’s upgraded SU-40 war planes tearing through the skies and even, in one particularly spectacular mission, of cruise missiles launched from 1,300km away from Syria in the Caspian Sea.
Western powers are still putting pressure on the Kremlin to halt attacks on moderate opposition forces they want to see at peace talks and focus the bombing on Islamic State.
But a cessation of hostilities brokered by the US in Munich last week has reinforced the sense that Russia has stolen the lead in Syria. Under the deal all parties in the conflict were supposed to stop fighting from February 19th to allow humanitarian aid in. The deal was selective, with Russia continuing its ferocious bombardment of Aleppo.
It has become clear over the past few months that Russia has a bigger game to play in Syria than just propping up a client dictator.
Syria, battered by a war that has claimed more than 250,000 lives and ravaged its infrastructure, is now centre stage in Putin’s drive to overturn the US-dominated post-Cold War world order and restore Russia as an major international power.
It helps that the US, discouraged by other Middle East policy failures, has dithered over Syria. But it’s a mark of how far Russia has stolen the lead in Syria that western officials now openly admit that they need Putin onside to bring peace to the region.
As Mark Galeotti, an expert on Russian defence matters, wrote in Foreign Affairs magazine last week, "Russia has bombed its way to a seat at the table."
Putin may find this gratifying, but the risk of the conflict spinning out of control is greater than ever before.
Russia's bombing campaign has already put the Kremlin on a collision course with Nato member Turkey, the ruler of Syria in Ottoman times and a major competitor with other regional powers for influence in the country.
One of the complications of the Syrian conflict is that in addition to the jihadis of Islamic State and the al-Qaeda linked Jabhat al-Nursa, there are many often rivalrous rebel groups involved, each with support from different international players. For Assad any group that challenges the Syrian government is a terrorist and Russia, for the most part, has been prepared to go along with that.
Turkey, furious that Russia had been bombing ethnic Turkish Turkoman rebels in Syria, shot down a Russian war plane in November allegedly for violating its air space.
Tensions between the two nations are now focused on Russia’s new alliance with Syrian Kurdish rebel groups – also supported by the US – who have put up a strong fight against Islamic State in north east Syria. Ankara is convinced that the Syrian Kurds have links with its long-time enemy, the Kurdish Workers Party or PKK which has been driving a renewed insurgency in southern Turkey.
After Turkey began shelling Syrian Kurdish positions across the border this month, Russia accused Ankara of planning a ground attack in Syria. A cross-border move by Turkey could provoke a Russian air attack that would then challenge Nato to honour Article 5 of its constitution and come to the the defence of its member state.
Saudi Arabia and other Sunni Gulf States, alarmed from the start about their regional Shia rival Iran’s support for Assad, are also considering deploying ground troops in Syria.
At a time when a wider is war is threatening and the west needs to present a united front, rifts are emerging in the European Union over the refugee crisis.
Russia's relentless bombing has unleashed a fresh wave of refugees fleeing Syria, placing an ever greater burden on neighbouring Turkey and the EU. Xenophobia is on the rise in Europe, strengthening the hand of a growing band of far-right politicians supportive of Putin's nationalistic policies.
One of these is Hungary's prime minister Viktor Orban, who has overseen the installation of razor-wire fences on his country's Croatian and Serbian borders to keep refugees out, a move that rights activists say contravenes international law. Yet speaking after a meeting with Orban in Moscow last week, Putin was full of praise for Hungary's policies.
“Hungary’s position and that of its prime minister is to defend European identity, the ideals of one’s country and its people,” Putin said following the talks .
The refugee crisis is weakening the European Union and diminishing its attractiveness to former Soviet countries that Putin considers part of Russia’s sphere of influence, Koert Debeuf, visiting research fellow at the Centre for the Resolution of Intractable Conflict at Oxford University, wrote on the Carnegie blog.
Putin was “pretty happy with the massive refugee influx into Europe as this is destabilising the region,” he added.
While western governments puzzle over Putin’s end-game in Syria, most analysts agree that the Kremlin doesn’t want to get bogged down in a protracted war in Syria or risk placing Russian troops on the ground.
Memories of the disastrous war waged by Moscow against an Islamist rebellion in Afghanistan that cost hundreds of thousands of lives and spurred the fall of the Soviet Union are still raw in Russia. And, while most Russians support Putin's Syrian adventure, public opinion could change if Russian troops began coming home in coffins.
Emboldened by gains on the battlefield, Assad is determined to press on to the end and regain control over the whole of Syria. “There is no choice for Syria except victory in the war for which it will have to pay a high price,” he said on February 16th.
Assad is likely to try to pressurise the Kremlin to stymie peace talks, warning that a new ruler in Syria would not protect Russian interests. "It's an example of the tail beginning to wag the dog," said Alexei Malashenko, an expert at the Carnegie Moscow Centre.
Cracks were beginning to surface in Moscow's relationship with Assad this week after Vitaly Churkin, Russia's envoy to the United Nations, said that the Syrian leader's position did not "chime" with that of its main ally.
Russia was working towards a peaceful resolution of the conflict in Syria and any attempt to take back full control of the country would be a futile effort, Churkin told the Russian newspaper Kommersant.
“If the Syrian authorities . . . follow Russia’s lead in the resolution of this crisis, then they have a chance to get out of it with their dignity intact.”
While western powers see no future for a lasting peace in Syria as long as Assad is in power, they may struggle to find a moderate opposition leader even remotely acceptable to all the warring parties.
Russia, which trained many Syrian military officers in Moscow during the Cold War, is better placed to identify rebels willing and capable of cutting a deal with Assad.