Politicians, diplomats and analysts have voiced grave concern over the possibility of recent sectarian violence in Iraq spilling over into the region, especially into Syria. Neoconservatives, who led the effort for the 2003 Iraq invasion, are objecting loudly to President Obama’s decision not to involve U.S. troops in the fight. We’ll ask historian and security expert, John Mearsheimer of the University of Chicago, about the possible consequences of Obama’s decision. He’ll also tell us his views on the reappearance of the neoconservatives in the media. Mearsheimer’s most recent book is The Tragedy of Great Power Politics. He also authored Why Leaders Lie: The Truth about Lying in International Politics. (photo: In this Sunday, Aug. 26, 2012 file photo, Syrian rebel fighter Tawfiq Hassan, 23, a former butcher, poses for a picture, after returning from fighting against Syrian army forces in Aleppo, at a rebel headquarters in Marea on the outskirts of Aleppo city, Syria. (AP Photo/Muhammed Muheisen, File))