And how could the US or Iraq weed them out? Until ISIS took over a huge chunk of Iraq, we were still arming, funding and training them as "freedom fighters" against Assad (whom we should be working with by now). Their poster boy is that photo-op they had with McCain.
It's just good crisis management. Taking advantage of a situation is what we do, but in a real out of control crisis don't make unnecessary changes with unknown consequences.
We’ve never trained or supported ISIS.
Please learn something before making false and slanderous accusations.
http://en.wikipedia.org/wiki/Syrian_opposition%E2%80%93Islamic_State_of_Iraq_and_the_Levant_conflict