Matthew Duss: During the 2008 campaign, Obama started—and won—a hugely significant debate about the proper uses of U.S. power. His declaration that he would not be afraid to talk to America’s enemies brought accusations of naiveté from both his Republican adversary John McCain and Democratic primary opponent Hillary Clinton, who would go on to begin implementing that same policy toward Iran as Obama’s first Secretary of State. Ending that mindset has proven a difficult task.