There hasn’t been a lot of reporting from Syria because it’s too dangerous and because Assad has banned them, but I get the impression that it is Russian weapons and Iranian fighters that are enabling Assad to maintain what little power he has left. There’s actually not much territory left he’s in control of. A no-fly zone has never been implemented in Syria by the US and allies like some have asked for (and there are some valid reasons for that), and Assad is the only one with air power, which is how he deploys barrel bombs. Russia are now moving air power into Syria too, greatly expanding their capacity. Russia themselves may not use barrel bombs, but they will be able to protect the Syrians from DAESH anti-aircraft munitions that they have captured. I think we can expect a lot more civilian casualties.

Russia does have a long time attachment to Syria and to Assad with lots of weapons going to Syria for many years and a number of Russian people there as well. Putin has been on a mission of sorts for some time, to somehow renew the Russia of old and this may be more of his desperate search of an authoritarian regime. Kind of a desperate try to hold on to its remaining levers of power. Like most of the U.S. interventions over the past several years, it does not look like a good move at this time.

One of the reasons I’m so worried – no one seems to have any good answers. I suspect the US etc would let Assad stay there for now if he wasn’t a Putin/Iran client.