U.S. doesn’t face much threat from Syria’s air power – rebels aren’t so lucky

"The Assad regime has dropped thousands of so-called “barrel bombs” — oil drums packed with explosive fertilizer that flight crews literally pick up and hurl out of helicopters. It’s a brutal and indiscriminate method of warfare. Russia and Iran play a large role in keeping the Syrian Air Force in the fight. Moscow is Syria’s largest arms supplier and has been for years."