The plan is for moderate anti-Assad armed groups to decouple themselves from al-Nusra, which will then be targeted by air strikes. It will not be easy to weaken or eliminate.There is a mysterious element in the US-Russian air campaign. Air strikes by both countries have been effective against Isis and al-Nusra, but they require ground troops to call in the air attacks against identifiable targets. More recently, it was, which it had held for two-and-a-half years, by the Iraqi army backed by US-led air strikes. It is closing many of its military and security bases, presumably suspecting that their function is well known and they will be targeted by US-led air strikes.

Source: Times of India September 12, 2016 14:51 UTC