Left Alone Against Syrian Army, U.S-trained Rebels Cannot Beat Islamic State

After Washington said it might lack the legal authority to defend them from Syrian troops, the main Western-backed political opposition said on Thursday that U.S.-trained rebels due to fight Islamic State will fail if they are not also protected from the Syrian army. Defense Secretary Ash Carter said on Wednesday that the United States did not appear to have clear-cut legal authority to protect Syrian rebels against attacks by Syrian government forces. Washington says Syrian President Bashar al-Assad has lost legitimacy, but it has in effect made common cause with him by leading air attacks against the Islamic State insurgency with Damascus's tacit blessing, forcing it to tread very warily.