Who are the Russians bombing in Syria and why?

Russia says it has begun air strikes in order to defeat Islamic State of Iraq and the Levant (Isil) and when pressed, Russian spokesmen say the US-led war has failed. But most of their first strikes have been against non-Isil opposition to the Assad regime.

Why would Russia bomb non-Isil groups?

The same spokesmen are sometimes vague - referring to Isil and terrorists in the same breath. By “terrorists” they mean the same as Bashar al-Assad - anyone part of the armed opposition. And it so happens that the gravest threat to the regime’s core areas - Damascus, and the central and western plains to the coast - comes from non-Isil rebels. Vladimir Putin, the Russian president has also said that he believes the survival of the Assad regime is very important, so it makes sense to target them first.

Has Russia not bombed Isil at all?

Reports are coming in that on Thursday morning there were strikes on a former regime air base near the Isil capital Raqqa and on Isil positions near Deir Ezzour city in eastern Syria. It is not quite clear whether there was any particular tactical purpose to these strikes.

If the regime is fighting Isil, surely anything that helps it is a good thing?

The Syrian war is a lot more complicated than that. The regime long ago gave up any hope of recapturing Isil-held areas in the near future. So the number of “live” battle-fronts between the regime and Isil are comparatively few. However, there is a fierce war going on between Isil and other rebel groups, so it may be that by bombing them the Russians are actually helping Isil. Russia denies that.

Its strategy may be that if it can help the regime defeat the non-Isil rebels, the world will gather round and help Damascus seize control of Isil-held areas too.

Are the non-Isil groups being bombed terrorists?

The groups they are bombing a spectrum of opposition groups from an alliance called Jaish al-Fatah - Army of Conquest - to brigades of “moderate” rebels backed and even, according to one account, trained by the US. Jaish al-Fatah made up of hardline groups that include Jabhat al-Nusra, which is aligned to al-Qaeda, so they are formally designated by the West and the United Nations as terrorists.

What will happen next?

The big question is whether these bombing raids are followed up by a ground offensive. A Telegraph source in Damascus said Hizbollah and the regime are preparing a major ground offensive on rebel-held parts of Homs following the Russian aerial bombardment while another report said Iranian reinforcements are arriving in Syria to assist in an attack also on rebel-held areas.

That will send a challenge to the rebels - and their backers in Turkey, Qatar and Saudi Arabia: do they also want to escalate the conflict?