The European Central Bank left its main interest rate unchanged, but ECB head Mario Draghi signaled the bank could purchase bonds and lower borrowing costs in the future. The battle for Aleppo raged on as Syrian rebels' handling of pro-government militiamen drew criticism. President Barack Obama announced new sanctions on Iran's energy sector. And India suffered the worst blackout in history, which left 670 million people without power. James Kitfield of National Journal, Susan Glasser of Foreign Policy magazine and David Ignatius of The Washington Post join Diane for analysis of the week's top international news stories.