U.S. has avoided attacking ISIS from the air if it's fighting the Syrian army

"The largest military force fighting IS in Syria is the Syrian army, as the former British chief of general staff Baron Richards pointed out last week. It is overstretched, but it has at least four effective combat divisions. It has always been a myth that it has not been fighting Isis as is proven by the horror films posted by the jihadists on YouTube, showing captive Syrian soldiers having their heads cut off. But the US has studiously avoided attacking Isis from the air if it is fighting the Syrian army" "The Syrian army has suffered 47,000 killed in action and its paramilitary forces lost a further 31,000 over the past four years,"