We aren't finding Sunni Arabs in ISIL-occupied Iraq willing and capable of resisting ISIL:
Officials admit little success in wooing new Sunni allies, beyond their fitful efforts to arm and supply the tribes who were already fighting the Islamic State — and mostly losing. So far, distrust of the Baghdad government’s intentions and its ability to protect the tribes has won out.
“There is an opportunity for the government to work with the tribes, but the facts on the ground are that ISIS has infiltrated these communities and depleted their ability to go against it,” said Ahmed Ali, an Iraq analyst at the Institute for the Study of War. “Time is not on the Iraqi government’s side.”
ISIL is too powerful in the Sunni Arab regions that ISIL controls for the Iraqi Sunni Arabs to risk rising up absent powerful Iraqi government forces coming to their rescue.
Thus, the hope that Iraqi forces could sail back into their lost regions taken by ISIL on a wave of Sunni Arabs angry at ISIL cannot take place. Angry the Sunni Arabs may be at ISIL brutality. But the Sunni Arabs cannot risk rising up before liberation is at hand.
So now we have the task of mounting an offensive into ISIL-held territory to the north and west of Baghdad, with Sunni Arabs at best rising up once the frontline reaches them.
A lot is riding on our ability to train Iraqi and Kurdish brigades to advance on Mosul from the south and northeast and to advance on Fallujah and Ramadi from the east, bolstered by our air power.
And I'd still like to see Jordan advance into Anbar from the west, too.
UPDATE: About the placement of that cart. But for that slaughtering thing that ISIL inflicts on the Sunni Arabs if they show signs of opposition, this would be a nice development:
Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, explained Wednesday what the United States and its allies have to do to defeat the Islamic State of Iraq and Syria (ISIS, also known as ISIL).
"When the Sunni population rejects it, that's the defeat mechanism," Dempsey said at the Defense One Summit in Washington, D.C.
It's a bridge too far to assume that Sunni Arabs deep in ISIL territory will rise up and help Iraqi forces advance rather than counting on an Iraqi advance to make it safe for Sunni Arabs under ISIL control to rise up to complement the American (and allied)-supported Iraqi offensives.
And the Syria front is even more of a problem, cart-positioning-wise.
UPDATE: This is certainly necessary:
The United States plans to buy arms for Sunni tribesmen in Iraq including AK-47s, rocket-propelled grenades and mortar rounds to help bolster the battle against Islamic State militants in Anbar province, according to a Pentagon document prepared for Congress.
But it is not sufficient. Those tribes have to have some confidence that rising up against ISIL doesn't simply make them and their families targets for slaughter by ISIL.