As President Barack Obama weighs military action in Syria, it remains unclear whether he will first seek congressional authorization. It is clear, however, that Obama once thought such authorization was necessary. “The president does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation,” candidate Obama told The Boston Globe in late 2007. He added that the president can only act unilaterally in “instances of self-defense.”