BEIRUT (Reuters) - Four months of Russian air strikes in Syria are taking their toll on rebel forces, strengthening the hand of a defiant President Bashar al-Assad as the United Nations struggles to get peace talks off the ground.
Insurgents in the west are being hit harder, while in eastern and central parts of the country, Islamic State is also under military pressure and is cutting fighters' pay as its oil-smuggling operations are hit by plunging prices.
