It's a bit tricky in the east of Syria, where Western, mostly US troops and their Kurdish and Arab allies are still in the game, so Deir-es-Zor, at least, will probably end up partitioned between the Syrian government and the Americans in the short run. But in the long run Assad gets it all back.
All that remains to do is reconquer the big enclave around Idlib in north-western Syria that is ruled by the al-Qaeda affiliate that used to be known as the Jabhat al-Nusra. (It has taken to changing its name every month or so in an attempt to disguise its origins.) But the Russian have promised to help Assad reconquer that territory too.
"The operation to destroy the fighters of the Isis and Jabhat al-Nusra terrorist groups on Syrian territory will continue until their complete and guaranteed destruction," promised General Lapin last week. Taking down al-Nusra will be a major enterprise, but it is quite doable because the Islamist outfit's former supporters in Turkey and Saudi Arabia have abandoned it.
Indeed, the Russian and Iranian effort to save Assad has been so successful that what once seemed impossible is becoming a reality: the whole country will be reunited under Assad's rule.
Much of the population that falls back under his control will hate it, and it is far from clear what will happen to the six million Syrians who fled abroad during the war. Most were anti-Assad, and many will never go home. Losing a civil war is a bitter experience, but one way or another everyone will have to come to terms with that fact.
How did the Russians (and their Iranian allies, who provided most of the fighting strength on the ground) win the war in two years when the United States had fumbled unsuccessfully with the issue since 2011? By being cold-blooded realists, deciding which was the lesser evil (Assad), and then single-mindedly focussing on a military victory.
By 2015 it was absolutely clear that there were only two possible victors in the Syrian civil war: the brutal but secular and reasonably competent men of the Ba'ath Party that has ruled Syria for the past half-century, or the violent religious fanatics of Isis and al-Nusra.
So while the US, equally appalled by both parties, spent years trying to find or invent a third 'moderate' option that never existed, Russia and Iran just went flat out to save Assad. (The Syrian army was within months of collapse when the Russians intervened in 2015.) They have succeeded, and the US will eventually have to pick up its marbles and go home.
And do bear in mind, as you contemplate the Syrian tragedy, that there are degrees of iniquity. Neither the Russian nor the Iranian regime is a model of democratic virtue, but Syria's Ba'ath Party is a great deal nastier, and there have certainly been times when its foreign saviours have had to hold their noses.
So do not exclude the possibility that the Russians might pressure the Ba'athists to change their leader once the fighting stops. Sending Bashar al-Assad into a safe and comfortable retirement at that point wouldn't really change anything in Syria, but it would put Russia's intervention in the war in a somewhat better light.
And what did Moscow get in return for its intervention? First and foremost, it prevented the emergence of an Islamist-ruled terrorist state quite close to Russia's own southern borders. (The Russian population is around one-tenth Muslim.) But it also demonstrated that it can be a very useful ally for other regimes that run into trouble. Unlike you-know-who.
*Gwynne Dyer is a independent journalist whose articles are published in 45 countries.