Nonetheless, the success of President Obama’s strategy in Syria clearly depends on the ability of the Syrian Opposition Coalition and the Free Syrian Army to fight ISIS. The good news is the FSA has established a command center outside the village of Marea in the strategically important province of Aleppo to direct and manage the battle against ISIS in northern Syria. And in August the Syrian Revolutionary Command Council, an alliance between FSA and other rebel factions, was formed to increase coordination and unity.

How can these rebel groups help the U.S. assault on ISIS? Even with the world’s most advanced intelligence reconnaissance and surveillance platforms, the U.S. military still needs “eyes on the ground” to round out the intelligence picture of ISIS’s capabilities, locations and vulnerabilities. Establishing an advise and assist relationship with the Free Syrian Army and tribal networks in eastern Syria would pay dividends for military planning. In late July, the Shaitat tribe in eastern Syria rose up against ISIS and drove them from the villages of Abu Hamam, Kashkiyeh and Ghranijup. The Shaitat have in turn faced brutal recriminations, with ISIS fighters capturing and slaughtering some 700 tribal members.

Such tribal discontent provides an opportunity to gain valuable targeting data regarding ISIS movements and arms caches. The U.S. should pay particular attention to the city of Abu Kamal in the lower Euphrates River valley, the site of a brutal battle this spring between ISIS and local tribal forces.