Marc Thiessen points to bad Syria policy for the current troubles in Iraq.
Second, he failed to support the moderate, pro-Western opposition in neighboring Syria — creating room for ISIS to fill the security vacuum. ISIS took over large swaths of Syrian territory, established a safe haven, used it to recruit and train thousands of jihadists, and prepared their current offensive in Iraq.
Obama set a red line and didn't fight on it.
Now, Iraqis are dying because of his decision.