US is supporting the rebels in Syria who are trying to bring down Assad's govt. ISIS is one of the rebels. So directly or indirectly, US is supporting ISIS in Syria.
But the same US is opposing the same ISIS in Iraq. why?
The only reason I can come up with is that because Syria is Russia-friendly, US is supporting ISIS there, but as Iraq is US-friendly, it opposes ISIS there. So say, if ISIS attacks Iran, US will support ISIS and if it attacks afghanistan, US will oppose ISIS.
what are your thoughts?