Syrian rebel fighters in the northern city of Aleppo in August. The Obama administration has been vetting rebel groups and decided that more than a dozen are moderate enough to arm. Zein al-Rifai/AFP/Getty Images hide caption

itoggle caption Zein al-Rifai/AFP/Getty Images

Iranian Foreign Minister Mohammad Javad Zarif speaks during a recent news conference in Rome. Zarif told NPR that the U.S. has been hesitant and contradictory in its approach to dealing with the self-declared Islamic State. Fabio Campana/EPA/Landov hide caption

itoggle caption Fabio Campana/EPA/Landov