Assad (Syria) is the Iranian/Turkish/Russian/Chinese linchpin. He's not going to be going easily. He's being continuously resupplied and he's slaughtering the other tribes (Sunni) who are attempting to remove his control. He's slaughtering the Kurds and demolishing the entire city of Homs and now is turning his attention forward. At the same time, he's being hit by the Turks who are using this event to continue their attack on the Kurds.
He's not only dug in, he was smart enough to protect the minorities so that they are also very fearful of a more extremist Muslim rule. His Alawites and wealthy circle certainly don't want the Sunni in control. Now with both China and Russian Veto power backing him in the UN and Iran as a military transport route?
Look to more death and destruction from Syria and Assad. The road to Damascus is Iran's land route to Lebanon and Hezbollah and through them, Gaza and Hamas.
Turkey wants to deal with the Kurds. Iran wants a pathway to Egypt. Hamas wants the end of Israel. Egypt and Saudi Arabia want to hold Iran back. There's a lot more of course, that's just peeling a partial first layer of a massive ME political onion.