A few debate-changing points of information about ISIS:
1. The trapped Yesidis were rescued not by US airstrikes but mainly by a ground offensive by kurdish groups -- anarchist-oriented YPG and nationalist-opportunist PKK who both represent a broad multiethnic regional population and have relatively progressive goals.
2. US aid recipient and NATO-ally Turkey grants open borders and medical assistance to ISIS fighters, and blockades the regional enemies of ISIS. This aid is largely from Saudi Arabia (private donors) and the Turkish government. Aid cartons have been photographed in an overrun ISIS base with a logo saying "Saudi Arabia and Turkey hand in hand."
3. Except for the attack on the Syrian airbase this week, ISIS has rarely fought the Syrian government, chosing instead to persecute internecine fighting with other antigovernment groups in Syria fighting against Assad (Free Syrian Army, Kurds, etc).