"Four days ago, government troops also captured Farzat hill, in an area near the site where the former leader of Jaish al-Islam, Zahran al-Alloush, was killed by a Syrian airstrike in December. Additionally, these advances help government soldiers to expand the corridor built from Marj as-Sultan Airbase towards central Damascus. Subsequently, Islamist rebels from Jaish al-Islam, Jabhat al-Nusra and the Free Syrian Army are unable to retreat from the southern pocket of East Ghouta into more secure rebel-held areas further north. " AMN
There is one road that runs north out what is not yet a completely closed encirclement and the gap between the jaws looks quite narrow. Them as want to escape should "get a move on." (idiomatic expression)
One can only hope that the Nusra Front and the other assorted jihadis will choose to fight to the death (one death or another).
The methodology and operational advice of the Russians is evident.
BTW, I think Kerry/Obama and Lavrov/Putin are putting together some dort of grand bargain, but, we will see. pl