Clearly military intervention just isn't working. The whole airstrike campaign was a good idea in theory, but you can't beat an insurgency from the air. Hell, you can't even win one from the ground, especially in the middle east. Look at Russia, then the US and then finally NATO in recent years. I'd like to say aid is the best way to go about this, but that doesn't work with radical groups either (Hotel Rwanda, anyone?)
I just don't even know what to think about this. Like Alaskun said, it's scary. Like legitimately scary. I'm kind of at a loss here, the emotionally charged option seems like the best one and that's killing them all. It's just not practical or even possible really.
Whether or not the US or Russia or whoever have funded terror groups throughout the years is a moot point. Mostly because when it happened, the landscape of global politics (probably the wrong way to say it, but you get the gist... I hope) was wildly different. When the US was funding and training the Mujahideen, wasn't it the '70's and Russia was in Afghanistan and the Cold War was still raging? Ultimately, the US figured that the Muj weren't going to end up killing them 30 or 40 years later, that's just the cost of doing business in a guerrilla war.