On September 16, General Dempsey, the Chairman of the Joint Chiefs, told a Senate committee that Mr. Obama had ruled out ground-air controllers called Joint Tactical Air Controller (JTACs). A platoon on a combat patrol tries always to include a JTAC.

Yesterday, Mr. Obama firmly reiterated, “I will not commit our armed forces to fighting another ground war in Iraq.” Three hours later, White House spokesman Josh Earnest, aboard Air Force One with the president, said American advisers in Iraq “could be in a position to even call in air strikes . . . They would not have a combat role. They would not be personally or directly engaging the enemy.”

Thus unless you strangle an enemy with your bare hands, you do not have a combat role. You are not fighting a ground war, although your radio call from the ground results in the deaths of the enemy 300 meters in front of you.

The sophomoric deceit of the White House is risible.

The good news is that our military has maneuvered the president into a backhanded endorsement of a limited ground war. Based on my years of reporting from the frontlines in Anbar Province and Mosul, I give the president a 10 percent chance of succeeding by using the Iraqi army to drive out the Islamic State. The odds are about 50–50 that the Sunni tribes, with dozens of American adviser teams and JTACs, can drive the group back into Syria. Those tribes, however, will not accede to being placed under the Iraqi Army and the Shiite government in Baghdad. Iran now controls Baghdad.

The odds of success are 100–1 without American adviser teams, each with an aggressive JTAC and sensible Rules of Engagement (heretofore entirely too rigid).

— Bing West is the author of six books on Iraq and Afghanistan, including One Million Steps: a Marine Platoon at War.