Russian air strikes put spring in step of Assad's army
Since the Russians waded in with air and missile strikes, and Iran stepped up its support on the ground directly and through Shia militias from around the region, Syrian President Bashar al-Assad's battered and under-manned army clearly has a new spring in its step.
In the past few days, his forces and their allies have begun offensives clearly aimed, initially at least, at regaining ground they lost to an alliance of non-Islamic State (IS) rebels since early this year.
The main areas currently in the sights of the regime and its allies are the Sahl al-Ghab, a large plain between Hama and Aleppo, and the mountains of northern Latakia province.
The rebels' penetration into these areas, following their capture of the capital of Idlib province in late March, represented a potentially deadly threat to the core of the regime's holdings, including the heartland of Assad's minority Alawite sect along the Latakia coast.
With President Assad publicly ringing the alarm bells - no doubt with an eye on the Russian and Iranian galleries - Moscow and Tehran decided to do what was necessary to prevent a collapse and shore up their strategic ally.
Since the imminent threat was being mounted not by IS but by the new Army of Conquest coalition of mainly Islamic rebel groups, backed by Saudi Arabia, Turkey and Qatar, it is not surprising that it seems to be those factions that are receiving most of the attention of Mr Putin's air strikes, as he tries to "stabilise the legitimate authorities" as he himself put it.
Reports from on the ground, which match the areas mentioned in Russian military statements, indicate that most of the air strikes are being carried out in direct support of the offensives on those two strategic fronts, although a few have been launched at IS targets in Raqqa and elsewhere.
IS militants are not located in most of the areas the Russians say they are hitting, though fighters from al-Nusra Front - the official al-Qaeda branch in Syria - are.
Tilting the balance
Al-Nusra is generally teamed up with the other groups in the Army of Conquest and other alliances on the ground, making it hard to isolate it and deal with it separately.
It clearly hasn't been a rout, despite intensive air strikes. The government forces and their allies have made some progress, capturing villages in northern Hama and southern Idlib provinces, but at a price.
A top Iranian Revolutionary Guards commander, Gen Hossein Hamedani, was killed in northern Syria and buried with much ceremony back in Iran at the weekend. A senior commander from the Lebanese Hezbollah forces is also among those reported to have died.
As the Americans and their coalition allies have found in operations in both Iraq and Syria, air support can be a crucial factor helping to hold the line or tilt the balance, but cannot win the battle unless teamed with cohesive, motivated ground forces, and even then progress can be slow against a stubborn enemy.
But the Russian intervention and escalation of Iranian involvement were greeted with alarm and outrage by Syrian opposition groups, which called on their international backers to step up their support.
A popular Saudi-origin cleric linked to al-Nusra Front, Abdullah al-Muhaysani, called on all the rebel factions to rally and launch an immediate counter-offensive on all fronts.
If they lost the initiative to the regime and the Russians, he warned in an internet video, they would risk "a series of collapses, and their future would be frightening".
The logical response to the Russian move would be for the Americans and their regional allies - Turkey, Qatar and Saudi Arabia - to escalate further their support for non-IS rebel groups, something that is already reported to be happening.
So the stage is set for an intense contest as the Russian-Iranian-government alliance strives to "stabilise the legitimate authorities". How far they might want to push that may depend on the degree of resistance on the ground.
Their primary goal must be to secure the areas deemed essential to the regime - "useful Syria", the core cities, from Deraa in the south through Damascus to Homs, Hama and the Latakia coast.
Driving the rebels out of "their" half of Aleppo in the north might be desirable but may turn out to be a tall order.
Would the situation then be ripe for negotiations on a settlement? President Putin seemed to hint in that direction in his TV interview at the weekend, when he said that his intervention was also aimed at "creating the conditions for a political compromise".
Significantly, he also at the weekend held a meeting with the Saudi Defence Minister, Prince Mohammed Bin Salman, who is backing some of the groups now being bombarded by the Russians.
There was no overt meeting of minds - the Saudis continued to insist that Bashar al-Assad must go, while for the Russians, he remains his country's legitimate leader. But the fact that they met, and both expressed a desire to keep up the dialogue, was interesting.
Such amiable contacts are likely to wither away, however, should the Russians and Iranians decide to try and push beyond a redressing of the balance, and pursue ambitions to dominate the whole country.
That could be a perilous route for them to take. Saudi Arabia regards itself as the custodian of the region's majority Sunni population, which could increasingly demonise both Moscow and Tehran, quite apart from revenge scenarios involving Islamist militants, thousands of them from the Russian or ex-Soviet territories.
Inflicting a crushing defeat on the Western-backed rebels, even if it were possible, would also risk pushing them literally and politically into the arms of IS. So an eventual stable stand-off might be a more desirable result.
But the degree of "compromise" involved in any potential settlement may depend on what balance is struck in the direct and proxy battles now getting under way on the ground.