Former Defense Secretary Robert Gates at the Boy Scouts of America's annual meeting in 2014. "There's no certainty about any of this," he says of the situation in Iraq. Mark Zaleski/AP hide caption

itoggle caption Mark Zaleski/AP

A car is engulfed by flames during clashes in Ramadi on Saturday. Islamic State militants drove Iraqi security forces out of the city, which is just 70 miles west of Baghdad. Reuters/Landov hide caption

itoggle caption Reuters/Landov