I edited, ghi, so you might not have seen the link, but the Benghazi commission also released their finding that the current admin had "armed" ISIS.
Now, the reason, apparently, was an intent to firewall the Shia superstate even then being melded from the now-abandoned Iraq south and Iran, but honestly, the whole plan smacks of too-clever-by-half hubris, imj, and, at the least could well foster another Shia vs. Sunni war.
GWB, while de facto fostering an increase in Sunni extremism, at least contained it, though, at this point, I'm tending to think the US was better off under the old policy of supporting friendly dictators. It's kind of hard to argue, looking at this mess, that we weren't better off with the Shah, Mubarak, Hussein, Assad, and Gaddafi.