Barry is In a tough spot here. The only real response is military intervention if the Iraqi army can't do the job. Sending Apache attack helicopters and A-10 will cause serious problems to ISIL but are more susceptible to being shot down. This would be one of the few times I would support a full fledged military intervention. I believe ISIL is partially our fault. By overthrowing Saddam and supporting rebels in Syria we left a huge power vacuum.
No, ISIS is not our fault. We overthrew Saddam Hussein and actually we did it about 12 years too late. The problem was over-deBaathizing Iraq. We completely disenfranchised many of the people who had any experience in running the country's military, government, and social institutions. And what made the situation even worse was as we did this, we didnt secure the various arms caches across the country because we were too busy looks for WMDs which had already long been destroyed. So, to review, we pissed people off and made sure they were armed.
And then Zarqawi and then it was ISI (or Al Qaeda in Iraq) facilitated sectarian civil war, attracted jihadists to Iraq. But this new strain of ISIS is the fault of al Maliki and the sectarian, divisive government. When we left Iraq and gave the keys to al Maliki and company, post surge, Iraq was in pretty good shape. Al Maliki went and disenfranchised everybody all over again, driving the Kurds and Sunnis off. The Kurds, to be fair, have been trying to fight ISIS, but the Sunnis by and large, figure, why bother? Hopefully al-Abadi is much more inclusive and can help bring the Sunnis and Kurds back together.
With the U.S. and now France, and maybe soon E.U./U.K. helping arm and supply Kurdish Peshmerga and with Iran helping Shia Iraqis, hopefully moving forward...with the occasional U.S. drone strike for some of the ISIS leadership, we can see some progress against ISIS. Like all these groups, eventually their barbarism will be a major factor in their downfall. Islamofascist groups like ISIS are innately self-destructive. They make more enemies than friends. It's just a matter of arming and equipping those enemies.