they are always underto be digging tunnels and trenches around the city and have placed tires filled on the out skirts. fighters are also making the most of the natural defenses, canals off of the you fray deez river. mohammed has more. >> reporter: the attacks in paris last week have had an effect far beyond the borders of france. french fighter jets launched their biggest raid in syria to date. their target, isil strong holds in raqqa. the u.s. and russia have also stepped up their campaigns. overnight, russian bombs hit oil fields controlled by isil. >> this is going to be another in many my view strategic mistake that the west is dealing with another -- a second war on terrorism, which is not going to be any different from the first war on terrorism that failed miserably, and replaced al-qaeda with daesh. >> reporter: russia began its air strikes in syria at the end of september. it has always said its main target is isil, but most of its bombs have hitterer to held by other groups opposed to its ally, president bashar al-assad. u.s. president barack obama says isil cannot be eli