This is interesting:
Assad, fighting to maintain his family's four-decade-old grip on Syria, appears to be focusing his military campaign on holding the main cities, along a highway axis running north of Homs to Hama and Aleppo and south to Damascus and Deraa, according to opposition sources.
This fits with my thinking of over a year ago that Assad had to pull back his troops to hold an arc from the Turkish border on the coast, and then down to the Jordanian and Israeli borders along the main highway mentioned above. My major difference is that I didn't include Aleppo in the area to be held.
Another difference is that by holding a core Syria over a year ago, it could be done with excess forces allowing strategic outposts in the non-core areas to be held until Assad could build up forces to expand out from his core Syria. As late as July 2012, I calculated that Assad could hold a shrunken Core Syria.
But Assad no longer has the troops to hold even a Core Syria. Strategypage estimates that Assad has 100,000 reliable ground forces (army and para-militaries). That's half of what I figured Assad would need to hold just the Core Syria.
Assad is a step behind in adjusting to reality. He tried to hold all of Syria when he had the troops only to hold a Core Syria. Now he tries to hold a Core Syria when he only has the troops to hold a rump Alawite state from the coast to the main north-south highway for some strategic depth. Even extending that border down to Damascus is just too much land to hold with the troops he has.
A strategic retreat isn't going to be easy. But expecting too few troops to hold what he has when those troops can only rotate out of the war in a pine box or by deserting/defecting is impossible. That's the reality that Assad hasn't accepted yet.