Former Secretary of Defense Bob Gates said that on Monday. Some retired military officers and many Republicans say the same thing with regard to ISIL and Iraq. I think those complaints miss the mark.
I believe that the underlying problem is that the Iraqi government doesn't have a strategy, or at least not an evident and feasible one. And the United States can advise and cajole and warn Iraq, but it can't control events. Nor could it control the fighting with 10,000 or 20,000 residual forces instead of the 2011 pullout or a similar number of ground troops today.
Fred Kaplan of Slate says Obama has to decide on his least worst option. None are good. I think that's true for the U.S. Government -- and also for the Iraqi government. Both governments want a stable and inclusive Iraq, with Iran's unavoidable influence still limited. But the Iraqi armed forces aren't fighting well, despite U.S. training and equipment. The Sunnis in Anbar fear both ISIL and the Shiite militias. Prime Minister Abadi is besieged by political opponents and thus has little maneuver room.
So what to do? Tony Cordesman of CSIS wants a "strong advisory effort." A Defense One poll of Pentagon officials found quite limited support for U.S. ground troops [31.4%] and bare majority support only for U.S. airstrikes and trying to enlist regional allies. Lots of luck.
David Ignatius wants Abadi to "empower the Sunnis" and notes that "This is still Iraq’s war, not America’s." That point is well worth keeping in mind.