It looks increasingly likely that the United States will expand its military operations against ISIS to Syria. Mark speak with William McCants of the Brookings Institution about the prospects and pitfalls of a US-led international military campaign against the Islamic State in Syria. They also discuss the role of another Islamist rebel group, al Nusra, in Syria's conflict and what might befall about 40 UN Peacekeepers in the Golan who were abducted by this group. Have a listen!