Assad won't go and when his military structure is degraded he uses gas. So without the extra Russian support Hizbullah, al-Quds and Iraqi reinforcements into the Syrian Army. He would be using large scale chemical attacks. And he will be bombed. So what happens when the reinforcements stop and he is in a degraded position.
UN: Gaza could be 'uninhabitable' by 2020 if trends continue (AP)
from the article: Why we should support the rebels in Syria