This is another example of a major government getting sucked into Guerrilla warfare with an enemy that holds mobile positions. It won't end well for occasional civilians or the US governent's budget.
It's sad because the US airstrikes will only fuel the propaganda fire to get locals affected by the airstrikes more interested in joining.
What Iraq needs is a hardcore dictator with a strong army and no patience for other groups trying to takeover his realm....willing to use chemical warfare to deter cells of civil unrest.....Wait....we killed him.
It sucks because the area was more stable before, despite the way we looked at it. ISIS is a mix of different kinds of people. It's not just a group of crazy, one dimensional extremists...it's less predictable because of how geographically widespread it is. The subgroups likely have different goals. We can only hope they have internal struggles for power after the american attacks that disrupt them and disband them. I just don't know if airstrikes will be enough.