What is known is that as PBS Frontline reported two weeks ago, while the administration has denied arming Syrian "rebels", i.e. the same ISIS militants that have crossed the border and are now fighting in Iraq...
... the reality is that it has. From: "Obama Says Not Arming Syrian Rebels, Syrian Rebels Say He Is"
To summarize: the US was arming and training the same Al Qaeda/ISIS groups of Jihadists, that it concurrently gave Iraq weapons to fight. And since the Iraq army has so far proven utterly incapable of any resistance, it is now up to US drones to "fight" the same "rebels" that the US itself was collaborating with until a month or so ago.
The clear winner here? The US military-industrial complex, of course, as well as the banks who lend money to the governments to fight wars provoked by various "developed nation" spy agencies.
Collateral damage? Millions of innocent people on the ground in Syria and Iraq, and everywhere else too.