The Syrian Air Force had been flying strikes off this base against IS target in eastern Syria. They did this until the base had to be evacuated to save the aircraft, mechanics, staff, etc. from the headchoppers. Tabqa had a spauadron of MIG-21s and another of MI-8 helicopters stationed there.
IS also holds Deir Az-Zor Air Base southeast of Tabqa. This is also on the Euphrates River. The loss of Tabqa air base is a serious defeat for the Syrian forces. IS has largely consolidated its hold on eastern Syria except for the Kurdish area in the far northeast. Syrian government air action against IS will have to be conducted from bases farther away in the west and to add to the damage IS captured a lot of additional equipment at Tabqa including many MANPADS (shoulder fired AA missiles)
IS appears to have executed 150 Syrian Air Force and Army prisoners after the base fell. The practice seems to be to offer Sunni Muslim military prisoners or civilians the chance to "sign up" but Shia and Alawis are generally killed after some period of abuse. Does anyone know any more about that?
The NY Times has taken note of the fact that the actual war is being run by former Iraqi Army officers (Saddam's Army) employed as techinal experts on the Tukhachevski model. To their conventional warfare planning skills from those days, there have now been added gerrilla experience hard won in their resistance to US forces. Hey, folks! We brought it on ourselves, or at least, the neocons brought it on us by throwing these men out on the street in 2003.
So, what will IS do next? pl