In January 2012, I wrote that Assad had to contract his realm to a core Syria in the west because he was losing ground trying to hold everything, and then rebuild his army to reconquer the entire country.
This article says Assad is planning to do just that. I think:
"The division of Syria is inevitable. The regime wants to control the coast, the two central cities of Hama and Homs and the capital Damascus," one Syrian political figure close to the regime said.
"The red lines for the authorities are the Damascus-Beirut highway and the Damascus-Homs highway, as well as the coast, with cities like Latakia and Tartus," he added, speaking on condition of anonymity. ...
"Iran urged Syrian authorities to face facts and change strategy by protecting only strategic zones," opposition figure Haytham Manna said. ...
Those are approximately 175,000 men from the army, pro-regime Syrian militias and foreign fighters including from Hezbollah and elsewhere.
The Observatory says 68,000 regime forces are among the 220,000 people killed since the conflict began.
The article says that Assad controls 50-60% of the population now.
I'm not sure if those population numbers include provincial capitals in the east. While in 2012 I thought that Assad would need to hold strategic outposts in the east, it is too late for that now.
Then I thought Assad could contract to prepare to counter-attack. Now Assad is contracting from exhaustion, so no relief columns will be heading east to rescue any strategic outposts.
Already, Aleppo is seen as outside Assad's core Syria. I did say it was a bridge too far for Assad.
Can 175,000 army, militia, Hezbollah, and Shia foreign legion troops hold perhaps 13 million people? Not if you assume Assad needs troops at 2% of the population to have a chance of pacifying and/or protecting the population. That rule of thumb implies Assad needs 260,000 troops. Or needs to control fewer than 9 million people.
At this point, I think Damascus is too much for Assad's casualty-wracked forces to hold. That has always seemed problematic to me. Yet holding Damascus means whatever Assad controls is still "Syria" with all the international recognition that provides. If he can't hold Damascus, he'd need to legally transfer his capital to the coast to argue he still gets the UN seat.
Would Russia send troops to bolster Assad's morale? That would be dramatic and would suit Putin's image of action. With the bonus of sticking it to America. Here's a real red line of Russian soldiers, eh? Hell, he'd probably be first off the transport plane (shirtless, of course) for the photo op.
Also note that Iran doesn't need all of Syria. They need access to Hezbollah in Lebanon in order to have a front against Israel. And Hezbollah needs that supply route, too. A core Syria does that.
As long as they have the money to bolster Assad (which is why Iran is counting on a faux nuclear deal with America, which would lift sanctions), that's fine as far as Iran is concerned.
Still, Syria claims they will counter-attack at Palmyra, which is well outside any core or rump Syria.
As I've said, you'd think that the idea that Iran is willing to fight Israel to the last Arab should be an obvious information warfare topic to alienate Arab Shias from Persian Shia Iran. If we thought of Iran as an enemy rather than a proto-partner, of course.
Assad is fighting for survival in western Syria where he can still function as an outpost of Iran; and will let America deal with ISIL which controls half of Syria's formal territory now. Let's not forget that both are our enemies.
Turkey has agreed to provide support, including air support, for non-ISIL Syrian rebels. That’s a dwindling group as ISIL continues fighting with rebels who refuse to come under ISIL command. Turkey has not signed a final deal but wanted everyone to know where the discussions were going. Meanwhile Russia and Iran are calling for a peaceful, political settlement of the Syrian civil war. Considering the ISIL attitude towards the rest of the world, that is not likely. Russia and Iran are both having financial problems (because of low oil prices) at home and support for the Assads is very unpopular. So far Russia and Iran are not willing to take the political hit for abandoning the Assads, but that aid is not as generous as it used to be.
If Russia and Iran won't be as generous, Assad must shrink to a core or rump Syria.
But Turkey is not going to let Assad survive unmolested as the big fish in a smaller pond.